Merge branch 'main' into ihalatci-extension-compat-test-report

.devcontainer/requirements.txt

@@ -1,4 +1,4 @@
-black==23.11.0
+black==24.3.0
 click==8.1.7
 isort==5.12.0
 mypy-extensions==1.0.0

src/backend/distributed/cdc/cdc_decoder_utils.c

@@ -346,12 +346,12 @@ CdcIsReferenceTableViaCatalog(Oid relationId)
 		return false;
 	}
 
-	Datum datumArray[Natts_pg_dist_partition];
-	bool isNullArray[Natts_pg_dist_partition];
-
 	Relation pgDistPartition = table_open(DistPartitionRelationId(), AccessShareLock);
 
 	TupleDesc tupleDescriptor = RelationGetDescr(pgDistPartition);
+	Datum *datumArray = (Datum *) palloc(tupleDescriptor->natts * sizeof(Datum));
+	bool *isNullArray = (bool *) palloc(tupleDescriptor->natts * sizeof(bool));
+
 	heap_deform_tuple(partitionTuple, tupleDescriptor, datumArray, isNullArray);
 
 	if (isNullArray[Anum_pg_dist_partition_partmethod - 1] ||
@@ -363,6 +363,8 @@ CdcIsReferenceTableViaCatalog(Oid relationId)
 		 */
 		heap_freetuple(partitionTuple);
 		table_close(pgDistPartition, NoLock);
+		pfree(datumArray);
+		pfree(isNullArray);
 		return false;
 	}
 
@@ -374,6 +376,8 @@ CdcIsReferenceTableViaCatalog(Oid relationId)
 
 	heap_freetuple(partitionTuple);
 	table_close(pgDistPartition, NoLock);
+	pfree(datumArray);
+	pfree(isNullArray);
 
 	/*
 	 * A table is a reference table when its partition method is 'none'

src/backend/distributed/deparser/citus_ruleutils.c

@@ -82,6 +82,7 @@ static void AppendStorageParametersToString(StringInfo stringBuffer,
 											List *optionList);
 static const char * convert_aclright_to_string(int aclright);
 static void simple_quote_literal(StringInfo buf, const char *val);
+static SubscriptingRef * TargetEntryExprFindSubsRef(Expr *expr);
 static void AddVacuumParams(ReindexStmt *reindexStmt, StringInfo buffer);
 static void process_acl_items(Acl *acl, const char *relationName,
 							  const char *attributeName, List **defs);
@@ -1715,3 +1716,255 @@ RoleSpecString(RoleSpec *spec, bool withQuoteIdentifier)
 		}
 	}
 }
+
+
+/*
+ * Recursively search an expression for a Param and return its paramid
+ * Intended for indirection management: UPDATE SET () = (SELECT )
+ * Does not cover all options but those supported by Citus.
+ */
+static int
+GetParamId(Node *expr)
+{
+	int paramid = 0;
+
+	if (expr == NULL)
+	{
+		return paramid;
+	}
+
+	/* If it's a Param, return its attnum */
+	if (IsA(expr, Param))
+	{
+		Param *param = (Param *) expr;
+		paramid = param->paramid;
+	}
+	/* If it's a FuncExpr, search in arguments */
+	else if (IsA(expr, FuncExpr))
+	{
+		FuncExpr *func = (FuncExpr *) expr;
+		ListCell *lc;
+
+		foreach(lc, func->args)
+		{
+			paramid = GetParamId((Node *) lfirst(lc));
+			if (paramid != 0)
+			{
+				break; /* Stop at the first valid paramid */
+			}
+		}
+	}
+
+	return paramid;
+}
+
+
+/*
+ * list_sort comparator to sort target list by paramid (in MULTIEXPR)
+ * Intended for indirection management: UPDATE SET () = (SELECT )
+ */
+static int
+target_list_cmp(const ListCell *a, const ListCell *b)
+{
+	TargetEntry *tleA = lfirst(a);
+	TargetEntry *tleB = lfirst(b);
+
+	/*
+	 * Deal with resjunk entries; sublinks are marked resjunk and
+	 * are placed at the end of the target list so this logic
+	 * ensures they stay grouped at the end of the target list:
+	 */
+	if (tleA->resjunk || tleB->resjunk)
+	{
+		return tleA->resjunk - tleB->resjunk;
+	}
+
+	int la = GetParamId((Node *) tleA->expr);
+	int lb = GetParamId((Node *) tleB->expr);
+
+	/*
+	 * Should be looking at legitimate param ids
+	 */
+	Assert(la > 0);
+	Assert(lb > 0);
+
+	/*
+	 * Return -1, 0 or 1 depending on if la is less than,
+	 * equal to or greater than lb
+	 */
+	return (la > lb) - (la < lb);
+}
+
+
+/*
+ * Used by get_update_query_targetlist_def() (in ruleutils) to reorder the target
+ * list on the left side of the update:
+ * SET () = (SELECT )
+ * Reordering the SELECT side only does not work, consider a case like:
+ * SET (col_1, col3) = (SELECT 1, 3), (col_2) = (SELECT 2)
+ * Without ensure_update_targetlist_in_param_order(), this will lead to an incorrect
+ * deparsed query:
+ * SET (col_1, col2) = (SELECT 1, 3), (col_3) = (SELECT 2)
+ */
+void
+ensure_update_targetlist_in_param_order(List *targetList)
+{
+	bool need_to_sort_target_list = false;
+	int previous_paramid = 0;
+	ListCell *l;
+
+	foreach(l, targetList)
+	{
+		TargetEntry *tle = (TargetEntry *) lfirst(l);
+
+		if (!tle->resjunk)
+		{
+			int paramid = GetParamId((Node *) tle->expr);
+			if (paramid < previous_paramid)
+			{
+				need_to_sort_target_list = true;
+				break;
+			}
+
+			previous_paramid = paramid;
+		}
+	}
+
+	if (need_to_sort_target_list)
+	{
+		list_sort(targetList, target_list_cmp);
+	}
+}
+
+
+/*
+ * ExpandMergedSubscriptingRefEntries takes a list of target entries and expands
+ * each one that references a SubscriptingRef node that indicates multiple (field)
+ * updates on the same attribute, which is applicable for array/json types atm.
+ */
+List *
+ExpandMergedSubscriptingRefEntries(List *targetEntryList)
+{
+	List *newTargetEntryList = NIL;
+	ListCell *tgtCell = NULL;
+
+	foreach(tgtCell, targetEntryList)
+	{
+		TargetEntry *targetEntry = (TargetEntry *) lfirst(tgtCell);
+		List *expandedTargetEntries = NIL;
+
+		Expr *expr = targetEntry->expr;
+		while (expr)
+		{
+			SubscriptingRef *subsRef = TargetEntryExprFindSubsRef(expr);
+			if (!subsRef)
+			{
+				break;
+			}
+
+			/*
+			 * Remove refexpr from the SubscriptingRef that we are about to
+			 * wrap in a new TargetEntry and save it for the next one.
+			 */
+			Expr *refexpr = subsRef->refexpr;
+			subsRef->refexpr = NULL;
+
+			/*
+			 * Wrap the Expr that holds SubscriptingRef (directly or indirectly)
+			 * in a new TargetEntry; note that it doesn't have a refexpr anymore.
+			 */
+			TargetEntry *newTargetEntry = copyObject(targetEntry);
+			newTargetEntry->expr = expr;
+			expandedTargetEntries = lappend(expandedTargetEntries, newTargetEntry);
+
+			/* now inspect the refexpr that SubscriptingRef at hand were holding */
+			expr = refexpr;
+		}
+
+		if (expandedTargetEntries == NIL)
+		{
+			/* return original entry since it doesn't hold a SubscriptingRef node */
+			newTargetEntryList = lappend(newTargetEntryList, targetEntry);
+		}
+		else
+		{
+			/*
+			 * Need to concat expanded target list entries in reverse order
+			 * to preserve ordering of the original target entry list.
+			 */
+			List *reversedTgtEntries = NIL;
+			ListCell *revCell = NULL;
+			foreach(revCell, expandedTargetEntries)
+			{
+				TargetEntry *tgtEntry = (TargetEntry *) lfirst(revCell);
+				reversedTgtEntries = lcons(tgtEntry, reversedTgtEntries);
+			}
+			newTargetEntryList = list_concat(newTargetEntryList, reversedTgtEntries);
+		}
+	}
+
+	return newTargetEntryList;
+}
+
+
+/*
+ * TargetEntryExprFindSubsRef searches given Expr --assuming that it is part
+ * of a target list entry-- to see if it directly (i.e.: itself) or indirectly
+ * (e.g.: behind some level of coercions) holds a SubscriptingRef node.
+ *
+ * Returns the original SubscriptingRef node on success or NULL otherwise.
+ *
+ * Note that it wouldn't add much value to use expression_tree_walker here
+ * since we are only interested in a subset of the fields of a few certain
+ * node types.
+ */
+static SubscriptingRef *
+TargetEntryExprFindSubsRef(Expr *expr)
+{
+	Node *node = (Node *) expr;
+	while (node)
+	{
+		if (IsA(node, FieldStore))
+		{
+			/*
+			 * ModifyPartialQuerySupported doesn't allow INSERT/UPDATE via
+			 * FieldStore. If we decide supporting such commands, then we
+			 * should take the first element of "newvals" list into account
+			 * here. This is because, to support such commands, we will need
+			 * to expand merged FieldStore into separate target entries too.
+			 *
+			 * For this reason, this block is not reachable atm and need to
+			 * uncomment the following if we decide supporting such commands.
+			 *
+			 * """
+			 *   FieldStore *fieldStore = (FieldStore *) node;
+			 *   node = (Node *) linitial(fieldStore->newvals);
+			 * """
+			 */
+			ereport(ERROR, (errmsg("unexpectedly got FieldStore object when "
+								   "generating shard query")));
+		}
+		else if (IsA(node, CoerceToDomain))
+		{
+			CoerceToDomain *coerceToDomain = (CoerceToDomain *) node;
+			if (coerceToDomain->coercionformat != COERCE_IMPLICIT_CAST)
+			{
+				/* not an implicit coercion, cannot reach to a SubscriptingRef */
+				break;
+			}
+
+			node = (Node *) coerceToDomain->arg;
+		}
+		else if (IsA(node, SubscriptingRef))
+		{
+			return (SubscriptingRef *) node;
+		}
+		else
+		{
+			/* got a node that we are not interested in */
+			break;
+		}
+	}
+
+	return NULL;
+}

src/backend/distributed/deparser/ruleutils_15.c

@@ -3509,6 +3509,8 @@ get_update_query_targetlist_def(Query *query, List *targetList,
 	SubLink    *cur_ma_sublink;
 	List	   *ma_sublinks;
 
+	targetList = ExpandMergedSubscriptingRefEntries(targetList);
+
 	/*
 	 * Prepare to deal with MULTIEXPR assignments: collect the source SubLinks
 	 * into a list.  We expect them to appear, in ID order, in resjunk tlist
@@ -3532,6 +3534,8 @@ get_update_query_targetlist_def(Query *query, List *targetList,
 				}
 			}
 		}
+
+		ensure_update_targetlist_in_param_order(targetList);
 	}
 	next_ma_cell = list_head(ma_sublinks);
 	cur_ma_sublink = NULL;

src/backend/distributed/deparser/ruleutils_16.c

@@ -3525,6 +3525,8 @@ get_update_query_targetlist_def(Query *query, List *targetList,
 	SubLink    *cur_ma_sublink;
 	List	   *ma_sublinks;
 
+	targetList = ExpandMergedSubscriptingRefEntries(targetList);
+
 	/*
 	 * Prepare to deal with MULTIEXPR assignments: collect the source SubLinks
 	 * into a list.  We expect them to appear, in ID order, in resjunk tlist
@@ -3548,6 +3550,8 @@ get_update_query_targetlist_def(Query *query, List *targetList,
 				}
 			}
 		}
+
+	        ensure_update_targetlist_in_param_order(targetList);
 	}
 	next_ma_cell = list_head(ma_sublinks);
 	cur_ma_sublink = NULL;

src/backend/distributed/deparser/ruleutils_17.c

@@ -3542,6 +3542,8 @@ get_update_query_targetlist_def(Query *query, List *targetList,
 	SubLink    *cur_ma_sublink;
 	List	   *ma_sublinks;
 
+	targetList = ExpandMergedSubscriptingRefEntries(targetList);
+
 	/*
 	 * Prepare to deal with MULTIEXPR assignments: collect the source SubLinks
 	 * into a list.  We expect them to appear, in ID order, in resjunk tlist
@@ -3565,6 +3567,8 @@ get_update_query_targetlist_def(Query *query, List *targetList,
 				}
 			}
 		}
+
+		ensure_update_targetlist_in_param_order(targetList);
 	}
 	next_ma_cell = list_head(ma_sublinks);
 	cur_ma_sublink = NULL;

src/backend/distributed/executor/adaptive_executor.c

@@ -760,7 +760,7 @@ AdaptiveExecutorPreExecutorRun(CitusScanState *scanState)
 	 */
 	LockPartitionsForDistributedPlan(distributedPlan);
 
-	ExecuteSubPlans(distributedPlan);
+	ExecuteSubPlans(distributedPlan, RequestedForExplainAnalyze(scanState));
 
 	scanState->finishedPreScan = true;
 }
@@ -3804,7 +3804,7 @@ PopAssignedPlacementExecution(WorkerSession *session)
 
 
 /*
- * PopAssignedPlacementExecution finds an executable task from the queue of assigned tasks.
+ * PopUnAssignedPlacementExecution finds an executable task from the queue of unassigned tasks.
  */
 static TaskPlacementExecution *
 PopUnassignedPlacementExecution(WorkerPool *workerPool)

src/backend/distributed/executor/citus_custom_scan.c

@@ -682,11 +682,13 @@ RegenerateTaskForFasthPathQuery(Job *workerJob)
 	}
 
 	bool isLocalTableModification = false;
+	bool delayedFastPath = false;
 	GenerateSingleShardRouterTaskList(workerJob,
 									  relationShardList,
 									  placementList,
 									  shardId,
-									  isLocalTableModification);
+									  isLocalTableModification,
+									  delayedFastPath);
 }
 
 

src/backend/distributed/executor/insert_select_executor.c

@@ -42,6 +42,7 @@
 #include "distributed/merge_planner.h"
 #include "distributed/metadata_cache.h"
 #include "distributed/multi_executor.h"
+#include "distributed/multi_explain.h"
 #include "distributed/multi_partitioning_utils.h"
 #include "distributed/multi_physical_planner.h"
 #include "distributed/multi_router_planner.h"
@@ -121,7 +122,7 @@ NonPushableInsertSelectExecScan(CustomScanState *node)
 			bool binaryFormat =
 				CanUseBinaryCopyFormatForTargetList(selectQuery->targetList);
 
-			ExecuteSubPlans(distSelectPlan);
+			ExecuteSubPlans(distSelectPlan, RequestedForExplainAnalyze(scanState));
 
 			/*
 			 * We have a separate directory for each transaction, so choosing

src/backend/distributed/executor/local_executor.c

@@ -313,6 +313,7 @@ ExecuteLocalTaskListExtended(List *taskList,
 		{
 			int taskNumParams = numParams;
 			Oid *taskParameterTypes = parameterTypes;
+			int taskType = GetTaskQueryType(task);
 
 			if (task->parametersInQueryStringResolved)
 			{
@@ -330,7 +331,7 @@ ExecuteLocalTaskListExtended(List *taskList,
 			 * for concatenated strings, we set queryStringList so that we can access
 			 * each query string.
 			 */
-			if (GetTaskQueryType(task) == TASK_QUERY_TEXT_LIST)
+			if (taskType == TASK_QUERY_TEXT_LIST)
 			{
 				List *queryStringList = task->taskQuery.data.queryStringList;
 				totalRowsProcessed +=
@@ -342,22 +343,31 @@ ExecuteLocalTaskListExtended(List *taskList,
 				continue;
 			}
 
-			Query *shardQuery = ParseQueryString(TaskQueryString(task),
+			if (taskType != TASK_QUERY_LOCAL_PLAN)
-												 taskParameterTypes,
+			{
-												 taskNumParams);
+				Query *shardQuery = ParseQueryString(TaskQueryString(task),
+													 taskParameterTypes,
+													 taskNumParams);
 
+				int cursorOptions = CURSOR_OPT_PARALLEL_OK;
 
-			int cursorOptions = CURSOR_OPT_PARALLEL_OK;
+				/*
-
+				 * Altough the shardQuery is local to this node, we prefer planner()
-			/*
+				 * over standard_planner(). The primary reason for that is Citus itself
-			 * Altough the shardQuery is local to this node, we prefer planner()
+				 * is not very tolarent standard_planner() calls that doesn't go through
-			 * over standard_planner(). The primary reason for that is Citus itself
+				 * distributed_planner() because of the way that restriction hooks are
-			 * is not very tolarent standard_planner() calls that doesn't go through
+				 * implemented. So, let planner to call distributed_planner() which
-			 * distributed_planner() because of the way that restriction hooks are
+				 * eventually calls standard_planner().
-			 * implemented. So, let planner to call distributed_planner() which
+				 */
-			 * eventually calls standard_planner().
+				localPlan = planner(shardQuery, NULL, cursorOptions, paramListInfo);
-			 */
+			}
-			localPlan = planner(shardQuery, NULL, cursorOptions, paramListInfo);
+			else
+			{
+				ereport(DEBUG2, (errmsg(
+									 "Local executor: Using task's cached local plan for task %u",
+									 task->taskId)));
+				localPlan = TaskQueryLocalPlan(task);
+			}
 		}
 
 		char *shardQueryString = NULL;
@@ -754,24 +764,6 @@ ExecuteTaskPlan(PlannedStmt *taskPlan, char *queryString,
 															 localPlacementIndex) :
 								 CreateDestReceiver(DestNone);
 
-	/* Create a QueryDesc for the query */
-	#if PG_VERSION_NUM >= PG_VERSION_18
-
-	/* PG18+: nine‐arg CreateQueryDesc with a CachedPlan slot */
-	QueryDesc *queryDesc = CreateQueryDesc(
-		taskPlan,          /* PlannedStmt *plannedstmt */
-		NULL,              /* CachedPlan *cplan (none) */
-		queryString,       /* const char *sourceText */
-		GetActiveSnapshot(),   /* Snapshot snapshot */
-		InvalidSnapshot,       /* Snapshot crosscheck_snapshot */
-		destReceiver,      /* DestReceiver *dest */
-		paramListInfo,     /* ParamListInfo params */
-		queryEnv,          /* QueryEnvironment *queryEnv */
-		0                  /* int instrument_options */
-		);
-	#else
-
-	/* PG15–17: eight‐arg CreateQueryDesc without CachedPlan */
 	QueryDesc *queryDesc = CreateQueryDesc(
 		taskPlan,          /* PlannedStmt *plannedstmt */
 		queryString,       /* const char *sourceText */
@@ -782,8 +774,6 @@ ExecuteTaskPlan(PlannedStmt *taskPlan, char *queryString,
 		queryEnv,          /* QueryEnvironment *queryEnv */
 		0                  /* int instrument_options */
 		);
-	#endif
-
 
 	ExecutorStart(queryDesc, eflags);
 

src/backend/distributed/executor/merge_executor.c

@@ -23,6 +23,7 @@
 #include "distributed/merge_executor.h"
 #include "distributed/merge_planner.h"
 #include "distributed/multi_executor.h"
+#include "distributed/multi_explain.h"
 #include "distributed/multi_partitioning_utils.h"
 #include "distributed/multi_router_planner.h"
 #include "distributed/repartition_executor.h"
@@ -132,7 +133,7 @@ ExecuteSourceAtWorkerAndRepartition(CitusScanState *scanState)
 	ereport(DEBUG1, (errmsg("Executing subplans of the source query and "
 							"storing the results at the respective node(s)")));
 
-	ExecuteSubPlans(distSourcePlan);
+	ExecuteSubPlans(distSourcePlan, RequestedForExplainAnalyze(scanState));
 
 	/*
 	 * We have a separate directory for each transaction, so choosing

src/backend/distributed/executor/multi_executor.c

@@ -688,7 +688,7 @@ ExecuteQueryIntoDestReceiver(Query *query, ParamListInfo params, DestReceiver *d
  * ExecutePlanIntoDestReceiver executes a query plan and sends results to the given
  * DestReceiver.
  */
-void
+uint64
 ExecutePlanIntoDestReceiver(PlannedStmt *queryPlan, ParamListInfo params,
 							DestReceiver *dest)
 {
@@ -701,21 +701,6 @@ ExecutePlanIntoDestReceiver(PlannedStmt *queryPlan, ParamListInfo params,
 	/* don't display the portal in pg_cursors, it is for internal use only */
 	portal->visible = false;
 
-#if PG_VERSION_NUM >= PG_VERSION_18
-
-	/* PostgreSQL 18+ adds a seventh “plansource” argument */
-	PortalDefineQuery(
-		portal,
-		NULL,                 /* no prepared statement name */
-		"",                   /* query text */
-		CMDTAG_SELECT,        /* command tag */
-		list_make1(queryPlan),/* list of PlannedStmt* */
-		NULL,                 /* no CachedPlan */
-		NULL                  /* no CachedPlanSource */
-		);
-#else
-
-	/* PostgreSQL 17-: six-arg signature */
 	PortalDefineQuery(
 		portal,
 		NULL,                 /* no prepared statement name */
@@ -724,11 +709,12 @@ ExecutePlanIntoDestReceiver(PlannedStmt *queryPlan, ParamListInfo params,
 		list_make1(queryPlan),/* list of PlannedStmt* */
 		NULL                  /* no CachedPlan */
 		);
-#endif
 
 	PortalStart(portal, params, eflags, GetActiveSnapshot());
 
 
+	QueryCompletion qc = { 0 };
+
 #if PG_VERSION_NUM >= PG_VERSION_18
 
 /* PG 18+: six-arg signature (drop the run_once bool) */
@@ -737,7 +723,7 @@ ExecutePlanIntoDestReceiver(PlannedStmt *queryPlan, ParamListInfo params,
 			  false,  /* isTopLevel */
 			  dest,   /* DestReceiver *dest */
 			  dest,   /* DestReceiver *altdest */
-			  NULL);  /* QueryCompletion *qc */
+			  &qc);  /* QueryCompletion *qc */
 #else
 
 /* PG 17-: original seven-arg signature */
@@ -747,10 +733,12 @@ ExecutePlanIntoDestReceiver(PlannedStmt *queryPlan, ParamListInfo params,
 			  true,   /* run_once */
 			  dest,   /* DestReceiver *dest */
 			  dest,   /* DestReceiver *altdest */
-			  NULL);  /* QueryCompletion *qc */
+			  &qc);  /* QueryCompletion *qc */
 #endif
 
 	PortalDrop(portal, false);
+
+	return qc.nprocessed;
 }
 
 

src/backend/distributed/executor/partitioned_intermediate_results.c

@@ -315,21 +315,6 @@ StartPortalForQueryExecution(const char *queryString)
 	/* don't display the portal in pg_cursors, it is for internal use only */
 	portal->visible = false;
 
-#if PG_VERSION_NUM >= PG_VERSION_18
-
-	/* PG 18+: new CachedPlanSource slot */
-	PortalDefineQuery(
-		portal,
-		NULL,                  /* no prepared‐stmt name */
-		queryString,           /* the SQL text */
-		CMDTAG_SELECT,         /* we’re running a SELECT */
-		list_make1(queryPlan), /* plan trees */
-		NULL,                  /* no CachedPlan */
-		NULL                   /* no CachedPlanSource */
-		);
-#else
-
-	/* PG 15–17: six‐arg signature */
 	PortalDefineQuery(
 		portal,
 		NULL,
@@ -338,7 +323,6 @@ StartPortalForQueryExecution(const char *queryString)
 		list_make1(queryPlan),
 		NULL                   /* no CachedPlan */
 		);
-#endif
 
 	int eflags = 0;
 	PortalStart(portal, NULL, eflags, GetActiveSnapshot());

src/backend/distributed/executor/subplan_execution.c

@@ -30,13 +30,22 @@ int MaxIntermediateResult = 1048576; /* maximum size in KB the intermediate resu
 /* when this is true, we enforce intermediate result size limit in all executors */
 int SubPlanLevel = 0;
 
+/*
+ * SubPlanExplainAnalyzeContext is both a memory context for storing
+ * subplans’ EXPLAIN ANALYZE output and a flag indicating that execution
+ * is running under EXPLAIN ANALYZE for subplans.
+ */
+MemoryContext SubPlanExplainAnalyzeContext = NULL;
+SubPlanExplainOutputData *SubPlanExplainOutput;
+extern uint8 TotalExplainOutputCapacity;
+extern uint8 NumTasksOutput;
 
 /*
  * ExecuteSubPlans executes a list of subplans from a distributed plan
  * by sequentially executing each plan from the top.
  */
 void
-ExecuteSubPlans(DistributedPlan *distributedPlan)
+ExecuteSubPlans(DistributedPlan *distributedPlan, bool explainAnalyzeEnabled)
 {
 	uint64 planId = distributedPlan->planId;
 	List *subPlanList = distributedPlan->subPlanList;
@@ -47,6 +56,19 @@ ExecuteSubPlans(DistributedPlan *distributedPlan)
 		return;
 	}
 
+	/*
+	 * If the root DistributedPlan has EXPLAIN ANALYZE enabled,
+	 * its subplans should also have EXPLAIN ANALYZE enabled.
+	 */
+	if (explainAnalyzeEnabled)
+	{
+		SubPlanExplainAnalyzeContext = GetMemoryChunkContext(distributedPlan);
+	}
+	else
+	{
+		SubPlanExplainAnalyzeContext = NULL;
+	}
+
 	HTAB *intermediateResultsHash = MakeIntermediateResultHTAB();
 	RecordSubplanExecutionsOnNodes(intermediateResultsHash, distributedPlan);
 
@@ -79,7 +101,23 @@ ExecuteSubPlans(DistributedPlan *distributedPlan)
 
 		TimestampTz startTimestamp = GetCurrentTimestamp();
 
-		ExecutePlanIntoDestReceiver(plannedStmt, params, copyDest);
+		uint64 nprocessed;
+
+		PG_TRY();
+		{
+			nprocessed =
+				ExecutePlanIntoDestReceiver(plannedStmt, params, copyDest);
+		}
+		PG_CATCH();
+		{
+			SubPlanExplainAnalyzeContext = NULL;
+			SubPlanExplainOutput = NULL;
+			TotalExplainOutputCapacity = 0;
+			NumTasksOutput = 0;
+			PG_RE_THROW();
+		}
+		PG_END_TRY();
+
 
 		/*
 		 * EXPLAIN ANALYZE instrumentations. Calculating these are very light-weight,
@@ -94,10 +132,24 @@ ExecuteSubPlans(DistributedPlan *distributedPlan)
 		subPlan->durationMillisecs += durationMicrosecs * MICRO_TO_MILLI_SECOND;
 
 		subPlan->bytesSentPerWorker = RemoteFileDestReceiverBytesSent(copyDest);
+		subPlan->ntuples = nprocessed;
 		subPlan->remoteWorkerCount = list_length(remoteWorkerNodeList);
 		subPlan->writeLocalFile = entry->writeLocalFile;
 
 		SubPlanLevel--;
+
+		/*
+		 * Save the EXPLAIN ANALYZE output(s) for later extraction in ExplainSubPlans().
+		 * Because the SubPlan context isn’t available during distributed execution,
+		 * pass the pointer as a global variable in SubPlanExplainOutput.
+		 */
+		subPlan->totalExplainOutput = SubPlanExplainOutput;
+		subPlan->numTasksOutput = NumTasksOutput;
+		SubPlanExplainOutput = NULL;
+		TotalExplainOutputCapacity = 0;
+		NumTasksOutput = 0;
 		FreeExecutorState(estate);
 	}
+
+	SubPlanExplainAnalyzeContext = NULL;
 }

src/backend/distributed/metadata/metadata_cache.c

@@ -729,12 +729,13 @@ PartitionMethodViaCatalog(Oid relationId)
 		return DISTRIBUTE_BY_INVALID;
 	}
 
-	Datum datumArray[Natts_pg_dist_partition];
-	bool isNullArray[Natts_pg_dist_partition];
-
 	Relation pgDistPartition = table_open(DistPartitionRelationId(), AccessShareLock);
 
 	TupleDesc tupleDescriptor = RelationGetDescr(pgDistPartition);
+
+	Datum *datumArray = (Datum *) palloc(tupleDescriptor->natts * sizeof(Datum));
+	bool *isNullArray = (bool *) palloc(tupleDescriptor->natts * sizeof(bool));
+
 	heap_deform_tuple(partitionTuple, tupleDescriptor, datumArray, isNullArray);
 
 	if (isNullArray[Anum_pg_dist_partition_partmethod - 1])
@@ -742,6 +743,8 @@ PartitionMethodViaCatalog(Oid relationId)
 		/* partition method cannot be NULL, still let's make sure */
 		heap_freetuple(partitionTuple);
 		table_close(pgDistPartition, NoLock);
+		pfree(datumArray);
+		pfree(isNullArray);
 		return DISTRIBUTE_BY_INVALID;
 	}
 
@@ -750,6 +753,8 @@ PartitionMethodViaCatalog(Oid relationId)
 
 	heap_freetuple(partitionTuple);
 	table_close(pgDistPartition, NoLock);
+	pfree(datumArray);
+	pfree(isNullArray);
 
 	return partitionMethodChar;
 }
@@ -768,12 +773,12 @@ PartitionColumnViaCatalog(Oid relationId)
 		return NULL;
 	}
 
-	Datum datumArray[Natts_pg_dist_partition];
-	bool isNullArray[Natts_pg_dist_partition];
-
 	Relation pgDistPartition = table_open(DistPartitionRelationId(), AccessShareLock);
 
 	TupleDesc tupleDescriptor = RelationGetDescr(pgDistPartition);
+	Datum *datumArray = (Datum *) palloc(tupleDescriptor->natts * sizeof(Datum));
+	bool *isNullArray = (bool *) palloc(tupleDescriptor->natts * sizeof(bool));
+
 	heap_deform_tuple(partitionTuple, tupleDescriptor, datumArray, isNullArray);
 
 	if (isNullArray[Anum_pg_dist_partition_partkey - 1])
@@ -781,6 +786,8 @@ PartitionColumnViaCatalog(Oid relationId)
 		/* partition key cannot be NULL, still let's make sure */
 		heap_freetuple(partitionTuple);
 		table_close(pgDistPartition, NoLock);
+		pfree(datumArray);
+		pfree(isNullArray);
 		return NULL;
 	}
 
@@ -795,6 +802,8 @@ PartitionColumnViaCatalog(Oid relationId)
 
 	heap_freetuple(partitionTuple);
 	table_close(pgDistPartition, NoLock);
+	pfree(datumArray);
+	pfree(isNullArray);
 
 	return partitionColumn;
 }
@@ -813,12 +822,13 @@ ColocationIdViaCatalog(Oid relationId)
 		return INVALID_COLOCATION_ID;
 	}
 
-	Datum datumArray[Natts_pg_dist_partition];
-	bool isNullArray[Natts_pg_dist_partition];
-
 	Relation pgDistPartition = table_open(DistPartitionRelationId(), AccessShareLock);
 
 	TupleDesc tupleDescriptor = RelationGetDescr(pgDistPartition);
+
+	Datum *datumArray = (Datum *) palloc(tupleDescriptor->natts * sizeof(Datum));
+	bool *isNullArray = (bool *) palloc(tupleDescriptor->natts * sizeof(bool));
+
 	heap_deform_tuple(partitionTuple, tupleDescriptor, datumArray, isNullArray);
 
 	if (isNullArray[Anum_pg_dist_partition_colocationid - 1])
@@ -826,6 +836,8 @@ ColocationIdViaCatalog(Oid relationId)
 		/* colocation id cannot be NULL, still let's make sure */
 		heap_freetuple(partitionTuple);
 		table_close(pgDistPartition, NoLock);
+		pfree(datumArray);
+		pfree(isNullArray);
 		return INVALID_COLOCATION_ID;
 	}
 
@@ -834,6 +846,8 @@ ColocationIdViaCatalog(Oid relationId)
 
 	heap_freetuple(partitionTuple);
 	table_close(pgDistPartition, NoLock);
+	pfree(datumArray);
+	pfree(isNullArray);
 
 	return colocationId;
 }
@@ -1741,10 +1755,11 @@ BuildCitusTableCacheEntry(Oid relationId)
 	}
 
 	MemoryContext oldContext = NULL;
-	Datum datumArray[Natts_pg_dist_partition];
-	bool isNullArray[Natts_pg_dist_partition];
 
 	TupleDesc tupleDescriptor = RelationGetDescr(pgDistPartition);
+	Datum *datumArray = (Datum *) palloc(tupleDescriptor->natts * sizeof(Datum));
+	bool *isNullArray = (bool *) palloc(tupleDescriptor->natts * sizeof(bool));
+
 	heap_deform_tuple(distPartitionTuple, tupleDescriptor, datumArray, isNullArray);
 
 	CitusTableCacheEntry *cacheEntry =
@@ -1797,7 +1812,7 @@ BuildCitusTableCacheEntry(Oid relationId)
 		cacheEntry->replicationModel = DatumGetChar(replicationModelDatum);
 	}
 
-	if (isNullArray[Anum_pg_dist_partition_autoconverted - 1])
+	if (isNullArray[GetAutoConvertedAttrIndexInPgDistPartition(tupleDescriptor)])
 	{
 		/*
 		 * We don't expect this to happen, but set it to false (the default value)
@@ -1808,7 +1823,7 @@ BuildCitusTableCacheEntry(Oid relationId)
 	else
 	{
 		cacheEntry->autoConverted = DatumGetBool(
-			datumArray[Anum_pg_dist_partition_autoconverted - 1]);
+			datumArray[GetAutoConvertedAttrIndexInPgDistPartition(tupleDescriptor)]);
 	}
 
 	heap_freetuple(distPartitionTuple);
@@ -1852,6 +1867,9 @@ BuildCitusTableCacheEntry(Oid relationId)
 
 	table_close(pgDistPartition, NoLock);
 
+	pfree(datumArray);
+	pfree(isNullArray);
+
 	cacheEntry->isValid = true;
 
 	return cacheEntry;
@@ -5011,10 +5029,13 @@ CitusTableTypeIdList(CitusTableType citusTableType)
 	TupleDesc tupleDescriptor = RelationGetDescr(pgDistPartition);
 
 	HeapTuple heapTuple = systable_getnext(scanDescriptor);
+	Datum *datumArray = (Datum *) palloc(tupleDescriptor->natts * sizeof(Datum));
+	bool *isNullArray = (bool *) palloc(tupleDescriptor->natts * sizeof(bool));
 	while (HeapTupleIsValid(heapTuple))
 	{
-		bool isNullArray[Natts_pg_dist_partition];
+		memset(datumArray, 0, tupleDescriptor->natts * sizeof(Datum));
-		Datum datumArray[Natts_pg_dist_partition];
+		memset(isNullArray, 0, tupleDescriptor->natts * sizeof(bool));
+
 		heap_deform_tuple(heapTuple, tupleDescriptor, datumArray, isNullArray);
 
 		Datum partMethodDatum = datumArray[Anum_pg_dist_partition_partmethod - 1];
@@ -5038,6 +5059,9 @@ CitusTableTypeIdList(CitusTableType citusTableType)
 		heapTuple = systable_getnext(scanDescriptor);
 	}
 
+	pfree(datumArray);
+	pfree(isNullArray);
+
 	systable_endscan(scanDescriptor);
 	table_close(pgDistPartition, AccessShareLock);
 

src/backend/distributed/metadata/metadata_sync.c

@@ -573,13 +573,17 @@ FetchRelationIdFromPgPartitionHeapTuple(HeapTuple heapTuple, TupleDesc tupleDesc
 {
 	Assert(heapTuple->t_tableOid == DistPartitionRelationId());
 
-	bool isNullArray[Natts_pg_dist_partition];
+	Datum *datumArray = (Datum *) palloc(tupleDesc->natts * sizeof(Datum));
-	Datum datumArray[Natts_pg_dist_partition];
+	bool *isNullArray = (bool *) palloc(tupleDesc->natts * sizeof(bool));
+
 	heap_deform_tuple(heapTuple, tupleDesc, datumArray, isNullArray);
 
 	Datum relationIdDatum = datumArray[Anum_pg_dist_partition_logicalrelid - 1];
 	Oid relationId = DatumGetObjectId(relationIdDatum);
 
+	pfree(datumArray);
+	pfree(isNullArray);
+
 	return relationId;
 }
 

src/backend/distributed/metadata/metadata_utility.c

@@ -812,6 +812,7 @@ GenerateSizeQueryOnMultiplePlacements(List *shardIntervalList,
 		{
 			partitionedShardNames = lappend(partitionedShardNames, quotedShardName);
 		}
+
 		/* for non-partitioned tables, we will use Postgres' size functions */
 		else
 		{
@@ -1919,23 +1920,22 @@ InsertIntoPgDistPartition(Oid relationId, char distributionMethod,
 {
 	char *distributionColumnString = NULL;
 
-	Datum newValues[Natts_pg_dist_partition];
-	bool newNulls[Natts_pg_dist_partition];
-
 	/* open system catalog and insert new tuple */
 	Relation pgDistPartition = table_open(DistPartitionRelationId(), RowExclusiveLock);
+	TupleDesc tupleDescriptor = RelationGetDescr(pgDistPartition);
+
+	Datum *newValues = (Datum *) palloc0(tupleDescriptor->natts * sizeof(Datum));
+	bool *newNulls = (bool *) palloc0(tupleDescriptor->natts * sizeof(bool));
 
 	/* form new tuple for pg_dist_partition */
-	memset(newValues, 0, sizeof(newValues));
-	memset(newNulls, false, sizeof(newNulls));
-
 	newValues[Anum_pg_dist_partition_logicalrelid - 1] =
 		ObjectIdGetDatum(relationId);
 	newValues[Anum_pg_dist_partition_partmethod - 1] =
 		CharGetDatum(distributionMethod);
 	newValues[Anum_pg_dist_partition_colocationid - 1] = UInt32GetDatum(colocationId);
 	newValues[Anum_pg_dist_partition_repmodel - 1] = CharGetDatum(replicationModel);
-	newValues[Anum_pg_dist_partition_autoconverted - 1] = BoolGetDatum(autoConverted);
+	newValues[GetAutoConvertedAttrIndexInPgDistPartition(tupleDescriptor)] =
+		BoolGetDatum(autoConverted);
 
 	/* set partkey column to NULL for reference tables */
 	if (distributionMethod != DISTRIBUTE_BY_NONE)
@@ -1951,7 +1951,7 @@ InsertIntoPgDistPartition(Oid relationId, char distributionMethod,
 		newNulls[Anum_pg_dist_partition_partkey - 1] = true;
 	}
 
-	HeapTuple newTuple = heap_form_tuple(RelationGetDescr(pgDistPartition), newValues,
+	HeapTuple newTuple = heap_form_tuple(tupleDescriptor, newValues,
 										 newNulls);
 
 	/* finally insert tuple, build index entries & register cache invalidation */
@@ -1963,6 +1963,9 @@ InsertIntoPgDistPartition(Oid relationId, char distributionMethod,
 
 	CommandCounterIncrement();
 	table_close(pgDistPartition, NoLock);
+
+	pfree(newValues);
+	pfree(newNulls);
 }
 
 
@@ -2154,13 +2157,13 @@ UpdatePlacementGroupId(uint64 placementId, int groupId)
 	ScanKeyData scanKey[1];
 	int scanKeyCount = 1;
 	bool indexOK = true;
-	Datum values[Natts_pg_dist_placement];
-	bool isnull[Natts_pg_dist_placement];
-	bool replace[Natts_pg_dist_placement];
 	bool colIsNull = false;
 
 	Relation pgDistPlacement = table_open(DistPlacementRelationId(), RowExclusiveLock);
 	TupleDesc tupleDescriptor = RelationGetDescr(pgDistPlacement);
+	Datum *values = (Datum *) palloc0(tupleDescriptor->natts * sizeof(Datum));
+	bool *isnull = (bool *) palloc0(tupleDescriptor->natts * sizeof(bool));
+	bool *replace = (bool *) palloc0(tupleDescriptor->natts * sizeof(bool));
 	ScanKeyInit(&scanKey[0], Anum_pg_dist_placement_placementid,
 				BTEqualStrategyNumber, F_INT8EQ, Int64GetDatum(placementId));
 
@@ -2177,8 +2180,6 @@ UpdatePlacementGroupId(uint64 placementId, int groupId)
 							   placementId)));
 	}
 
-	memset(replace, 0, sizeof(replace));
-
 	values[Anum_pg_dist_placement_groupid - 1] = Int32GetDatum(groupId);
 	isnull[Anum_pg_dist_placement_groupid - 1] = false;
 	replace[Anum_pg_dist_placement_groupid - 1] = true;
@@ -2197,6 +2198,10 @@ UpdatePlacementGroupId(uint64 placementId, int groupId)
 
 	systable_endscan(scanDescriptor);
 	table_close(pgDistPlacement, NoLock);
+
+	pfree(values);
+	pfree(isnull);
+	pfree(replace);
 }
 
 
@@ -2210,12 +2215,13 @@ UpdatePgDistPartitionAutoConverted(Oid citusTableId, bool autoConverted)
 	ScanKeyData scanKey[1];
 	int scanKeyCount = 1;
 	bool indexOK = true;
-	Datum values[Natts_pg_dist_partition];
-	bool isnull[Natts_pg_dist_partition];
-	bool replace[Natts_pg_dist_partition];
 
 	Relation pgDistPartition = table_open(DistPartitionRelationId(), RowExclusiveLock);
 	TupleDesc tupleDescriptor = RelationGetDescr(pgDistPartition);
+	Datum *values = (Datum *) palloc0(tupleDescriptor->natts * sizeof(Datum));
+	bool *isnull = (bool *) palloc0(tupleDescriptor->natts * sizeof(bool));
+	bool *replace = (bool *) palloc0(tupleDescriptor->natts * sizeof(bool));
+
 	ScanKeyInit(&scanKey[0], Anum_pg_dist_partition_logicalrelid,
 				BTEqualStrategyNumber, F_OIDEQ, ObjectIdGetDatum(citusTableId));
 
@@ -2231,11 +2237,10 @@ UpdatePgDistPartitionAutoConverted(Oid citusTableId, bool autoConverted)
 							   citusTableId)));
 	}
 
-	memset(replace, 0, sizeof(replace));
+	int autoconvertedindex = GetAutoConvertedAttrIndexInPgDistPartition(tupleDescriptor);
-
+	values[autoconvertedindex] = BoolGetDatum(autoConverted);
-	values[Anum_pg_dist_partition_autoconverted - 1] = BoolGetDatum(autoConverted);
+	isnull[autoconvertedindex] = false;
-	isnull[Anum_pg_dist_partition_autoconverted - 1] = false;
+	replace[autoconvertedindex] = true;
-	replace[Anum_pg_dist_partition_autoconverted - 1] = true;
 
 	heapTuple = heap_modify_tuple(heapTuple, tupleDescriptor, values, isnull, replace);
 
@@ -2247,6 +2252,10 @@ UpdatePgDistPartitionAutoConverted(Oid citusTableId, bool autoConverted)
 
 	systable_endscan(scanDescriptor);
 	table_close(pgDistPartition, NoLock);
+
+	pfree(values);
+	pfree(isnull);
+	pfree(replace);
 }
 
 
@@ -2286,12 +2295,13 @@ UpdateDistributionColumn(Oid relationId, char distributionMethod, Var *distribut
 	ScanKeyData scanKey[1];
 	int scanKeyCount = 1;
 	bool indexOK = true;
-	Datum values[Natts_pg_dist_partition];
-	bool isnull[Natts_pg_dist_partition];
-	bool replace[Natts_pg_dist_partition];
 
 	Relation pgDistPartition = table_open(DistPartitionRelationId(), RowExclusiveLock);
 	TupleDesc tupleDescriptor = RelationGetDescr(pgDistPartition);
+	Datum *values = (Datum *) palloc0(tupleDescriptor->natts * sizeof(Datum));
+	bool *isnull = (bool *) palloc0(tupleDescriptor->natts * sizeof(bool));
+	bool *replace = (bool *) palloc0(tupleDescriptor->natts * sizeof(bool));
+
 	ScanKeyInit(&scanKey[0], Anum_pg_dist_partition_logicalrelid,
 				BTEqualStrategyNumber, F_OIDEQ, ObjectIdGetDatum(relationId));
 
@@ -2307,8 +2317,6 @@ UpdateDistributionColumn(Oid relationId, char distributionMethod, Var *distribut
 							   relationId)));
 	}
 
-	memset(replace, 0, sizeof(replace));
-
 	replace[Anum_pg_dist_partition_partmethod - 1] = true;
 	values[Anum_pg_dist_partition_partmethod - 1] = CharGetDatum(distributionMethod);
 	isnull[Anum_pg_dist_partition_partmethod - 1] = false;
@@ -2317,9 +2325,10 @@ UpdateDistributionColumn(Oid relationId, char distributionMethod, Var *distribut
 	values[Anum_pg_dist_partition_colocationid - 1] = UInt32GetDatum(colocationId);
 	isnull[Anum_pg_dist_partition_colocationid - 1] = false;
 
-	replace[Anum_pg_dist_partition_autoconverted - 1] = true;
+	int autoconvertedindex = GetAutoConvertedAttrIndexInPgDistPartition(tupleDescriptor);
-	values[Anum_pg_dist_partition_autoconverted - 1] = BoolGetDatum(false);
+	replace[autoconvertedindex] = true;
-	isnull[Anum_pg_dist_partition_autoconverted - 1] = false;
+	values[autoconvertedindex] = BoolGetDatum(false);
+	isnull[autoconvertedindex] = false;
 
 	char *distributionColumnString = nodeToString((Node *) distributionColumn);
 
@@ -2337,6 +2346,10 @@ UpdateDistributionColumn(Oid relationId, char distributionMethod, Var *distribut
 
 	systable_endscan(scanDescriptor);
 	table_close(pgDistPartition, NoLock);
+
+	pfree(values);
+	pfree(isnull);
+	pfree(replace);
 }
 
 
@@ -2380,12 +2393,13 @@ UpdateNoneDistTableMetadata(Oid relationId, char replicationModel, uint32 coloca
 	ScanKeyData scanKey[1];
 	int scanKeyCount = 1;
 	bool indexOK = true;
-	Datum values[Natts_pg_dist_partition];
-	bool isnull[Natts_pg_dist_partition];
-	bool replace[Natts_pg_dist_partition];
 
 	Relation pgDistPartition = table_open(DistPartitionRelationId(), RowExclusiveLock);
 	TupleDesc tupleDescriptor = RelationGetDescr(pgDistPartition);
+	Datum *values = (Datum *) palloc0(tupleDescriptor->natts * sizeof(Datum));
+	bool *isnull = (bool *) palloc0(tupleDescriptor->natts * sizeof(bool));
+	bool *replace = (bool *) palloc0(tupleDescriptor->natts * sizeof(bool));
+
 	ScanKeyInit(&scanKey[0], Anum_pg_dist_partition_logicalrelid,
 				BTEqualStrategyNumber, F_OIDEQ, ObjectIdGetDatum(relationId));
 
@@ -2401,8 +2415,6 @@ UpdateNoneDistTableMetadata(Oid relationId, char replicationModel, uint32 coloca
 							   relationId)));
 	}
 
-	memset(replace, 0, sizeof(replace));
-
 	values[Anum_pg_dist_partition_colocationid - 1] = UInt32GetDatum(colocationId);
 	isnull[Anum_pg_dist_partition_colocationid - 1] = false;
 	replace[Anum_pg_dist_partition_colocationid - 1] = true;
@@ -2411,9 +2423,10 @@ UpdateNoneDistTableMetadata(Oid relationId, char replicationModel, uint32 coloca
 	isnull[Anum_pg_dist_partition_repmodel - 1] = false;
 	replace[Anum_pg_dist_partition_repmodel - 1] = true;
 
-	values[Anum_pg_dist_partition_autoconverted - 1] = BoolGetDatum(autoConverted);
+	int autoconvertedindex = GetAutoConvertedAttrIndexInPgDistPartition(tupleDescriptor);
-	isnull[Anum_pg_dist_partition_autoconverted - 1] = false;
+	values[autoconvertedindex] = BoolGetDatum(autoConverted);
-	replace[Anum_pg_dist_partition_autoconverted - 1] = true;
+	isnull[autoconvertedindex] = false;
+	replace[autoconvertedindex] = true;
 
 	heapTuple = heap_modify_tuple(heapTuple, tupleDescriptor, values, isnull, replace);
 
@@ -2424,6 +2437,10 @@ UpdateNoneDistTableMetadata(Oid relationId, char replicationModel, uint32 coloca
 
 	systable_endscan(scanDescriptor);
 	table_close(pgDistPartition, NoLock);
+
+	pfree(values);
+	pfree(isnull);
+	pfree(replace);
 }
 
 
@@ -3149,8 +3166,8 @@ ScheduleBackgroundTask(int64 jobId, Oid owner, char *command, int dependingTaskC
 
 		values[Anum_pg_dist_background_task_nodes_involved - 1] =
 			IntArrayToDatum(nodesInvolvedCount, nodesInvolved);
-		nulls[Anum_pg_dist_background_task_nodes_involved - 1] = (nodesInvolvedCount ==
+		nulls[Anum_pg_dist_background_task_nodes_involved - 1] =
-																  0);
+			(nodesInvolvedCount == 0);
 
 		HeapTuple newTuple = heap_form_tuple(RelationGetDescr(pgDistBackgroundTask),
 											 values, nulls);
@@ -4420,3 +4437,23 @@ UnblockDependingBackgroundTasks(BackgroundTask *task)
 
 	table_close(pgDistBackgroundTasksDepend, NoLock);
 }
+
+
+/*
+ * GetAutoConvertedAttrIndexInPgDistPartition returns attrnum for autoconverted attr.
+ *
+ * autoconverted attr was added to table pg_dist_partition using alter operation after
+ * the version where Citus started supporting downgrades, and it's only column that we've
+ * introduced to pg_dist_partition since then.
+ *
+ * And in case of a downgrade + upgrade, tupleDesc->natts becomes greater than
+ * Natts_pg_dist_partition and when this happens, then we know that attrnum autoconverted is
+ * not Anum_pg_dist_partition_autoconverted anymore but tupleDesc->natts - 1.
+ */
+int
+GetAutoConvertedAttrIndexInPgDistPartition(TupleDesc tupleDesc)
+{
+	return TupleDescSize(tupleDesc) == Natts_pg_dist_partition
+		   ? (Anum_pg_dist_partition_autoconverted - 1)
+		   : tupleDesc->natts - 1;
+}

src/backend/distributed/metadata/node_metadata.c

@@ -2930,7 +2930,7 @@ InsertNodeRow(int nodeid, char *nodeName, int32 nodePort, NodeMetadata *nodeMeta
 	TupleDesc tupleDescriptor = RelationGetDescr(pgDistNode);
 	HeapTuple heapTuple = heap_form_tuple(tupleDescriptor, values, isNulls);
 
-	CatalogTupleInsert(pgDistNode, heapTuple);
+	CATALOG_INSERT_WITH_SNAPSHOT(pgDistNode, heapTuple);
 
 	CitusInvalidateRelcacheByRelid(DistNodeRelationId());
 

src/backend/distributed/planner/deparse_shard_query.c

@@ -439,6 +439,27 @@ SetTaskQueryStringList(Task *task, List *queryStringList)
 }
 
 
+void
+SetTaskQueryPlan(Task *task, Query *query, PlannedStmt *localPlan)
+{
+	Assert(localPlan != NULL);
+	task->taskQuery.queryType = TASK_QUERY_LOCAL_PLAN;
+	task->taskQuery.data.localCompiled = (LocalCompilation *) palloc0(
+		sizeof(LocalCompilation));
+	task->taskQuery.data.localCompiled->query = query;
+	task->taskQuery.data.localCompiled->plan = localPlan;
+	task->queryCount = 1;
+}
+
+
+PlannedStmt *
+TaskQueryLocalPlan(Task *task)
+{
+	Assert(task->taskQuery.queryType == TASK_QUERY_LOCAL_PLAN);
+	return task->taskQuery.data.localCompiled->plan;
+}
+
+
 /*
  * DeparseTaskQuery is a general way of deparsing a query based on a task.
  */
@@ -524,6 +545,26 @@ TaskQueryString(Task *task)
 	{
 		return task->taskQuery.data.queryStringLazy;
 	}
+	else if (taskQueryType == TASK_QUERY_LOCAL_PLAN)
+	{
+		Query *query = task->taskQuery.data.localCompiled->query;
+		Assert(query != NULL);
+
+		/*
+		 * Use the query of the local compilation to generate the
+		 * query string. For local compiled tasks, the query is retained
+		 * for this purpose, which may be EXPLAIN ANALYZing the task, or
+		 * command logging. Generating the query string on the fly is
+		 * acceptable because the plan of the local compilation is used
+		 * for query execution.
+		 */
+		MemoryContext previousContext = MemoryContextSwitchTo(GetMemoryChunkContext(
+																  query));
+		UpdateRelationToShardNames((Node *) query, task->relationShardList);
+		MemoryContextSwitchTo(previousContext);
+		return AnnotateQuery(DeparseTaskQuery(task, query),
+							 task->partitionKeyValue, task->colocationId);
+	}
 
 	Query *jobQueryReferenceForLazyDeparsing =
 		task->taskQuery.data.jobQueryReferenceForLazyDeparsing;

src/backend/distributed/planner/distributed_planner.c

@@ -135,13 +135,13 @@ static void AdjustReadIntermediateResultsCostInternal(RelOptInfo *relOptInfo,
 													  Const *resultFormatConst);
 static List * OuterPlanParamsList(PlannerInfo *root);
 static List * CopyPlanParamList(List *originalPlanParamList);
-static PlannerRestrictionContext * CreateAndPushPlannerRestrictionContext(void);
+static PlannerRestrictionContext * CreateAndPushPlannerRestrictionContext(
+	FastPathRestrictionContext *fastPathContext);
 static PlannerRestrictionContext * CurrentPlannerRestrictionContext(void);
 static void PopPlannerRestrictionContext(void);
 static void ResetPlannerRestrictionContext(
 	PlannerRestrictionContext *plannerRestrictionContext);
-static PlannedStmt * PlanFastPathDistributedStmt(DistributedPlanningContext *planContext,
+static PlannedStmt * PlanFastPathDistributedStmt(DistributedPlanningContext *planContext);
-												 Node *distributionKeyValue);
 static PlannedStmt * PlanDistributedStmt(DistributedPlanningContext *planContext,
 										 int rteIdCounter);
 static RTEListProperties * GetRTEListProperties(List *rangeTableList);
@@ -166,7 +166,7 @@ distributed_planner(Query *parse,
 {
 	bool needsDistributedPlanning = false;
 	bool fastPathRouterQuery = false;
-	Node *distributionKeyValue = NULL;
+	FastPathRestrictionContext fastPathContext = { 0 };
 
 	List *rangeTableList = ExtractRangeTableEntryList(parse);
 
@@ -191,8 +191,7 @@ distributed_planner(Query *parse,
 											&maybeHasForeignDistributedTable);
 		if (needsDistributedPlanning)
 		{
-			fastPathRouterQuery = FastPathRouterQuery(parse, &distributionKeyValue);
+			fastPathRouterQuery = FastPathRouterQuery(parse, &fastPathContext);
-
 			if (maybeHasForeignDistributedTable)
 			{
 				WarnIfListHasForeignDistributedTable(rangeTableList);
@@ -247,8 +246,9 @@ distributed_planner(Query *parse,
 	 */
 	HideCitusDependentObjectsOnQueriesOfPgMetaTables((Node *) parse, NULL);
 
-	/* create a restriction context and put it at the end if context list */
+	/* create a restriction context and put it at the end of context list */
-	planContext.plannerRestrictionContext = CreateAndPushPlannerRestrictionContext();
+	planContext.plannerRestrictionContext = CreateAndPushPlannerRestrictionContext(
+		&fastPathContext);
 
 	/*
 	 * We keep track of how many times we've recursed into the planner, primarily
@@ -264,7 +264,7 @@ distributed_planner(Query *parse,
 	{
 		if (fastPathRouterQuery)
 		{
-			result = PlanFastPathDistributedStmt(&planContext, distributionKeyValue);
+			result = PlanFastPathDistributedStmt(&planContext);
 		}
 		else
 		{
@@ -649,30 +649,21 @@ IsMultiTaskPlan(DistributedPlan *distributedPlan)
  * the FastPathPlanner.
  */
 static PlannedStmt *
-PlanFastPathDistributedStmt(DistributedPlanningContext *planContext,
+PlanFastPathDistributedStmt(DistributedPlanningContext *planContext)
-							Node *distributionKeyValue)
 {
 	FastPathRestrictionContext *fastPathContext =
 		planContext->plannerRestrictionContext->fastPathRestrictionContext;
+	Assert(fastPathContext != NULL);
+	Assert(fastPathContext->fastPathRouterQuery);
 
-	planContext->plannerRestrictionContext->fastPathRestrictionContext->
+	FastPathPreprocessParseTree(planContext->query);
-	fastPathRouterQuery = true;
 
-	if (distributionKeyValue == NULL)
+	if (!fastPathContext->delayFastPathPlanning)
 	{
-		/* nothing to record */
+		planContext->plan = FastPathPlanner(planContext->originalQuery,
+											planContext->query,
+											planContext->boundParams);
 	}
-	else if (IsA(distributionKeyValue, Const))
-	{
-		fastPathContext->distributionKeyValue = (Const *) distributionKeyValue;
-	}
-	else if (IsA(distributionKeyValue, Param))
-	{
-		fastPathContext->distributionKeyHasParam = true;
-	}
-
-	planContext->plan = FastPathPlanner(planContext->originalQuery, planContext->query,
-										planContext->boundParams);
 
 	return CreateDistributedPlannedStmt(planContext);
 }
@@ -803,6 +794,8 @@ CreateDistributedPlannedStmt(DistributedPlanningContext *planContext)
 		RaiseDeferredError(distributedPlan->planningError, ERROR);
 	}
 
+	CheckAndBuildDelayedFastPathPlan(planContext, distributedPlan);
+
 	/* remember the plan's identifier for identifying subplans */
 	distributedPlan->planId = planId;
 
@@ -2407,13 +2400,15 @@ CopyPlanParamList(List *originalPlanParamList)
 
 
 /*
- * CreateAndPushPlannerRestrictionContext creates a new relation restriction context
+ * CreateAndPushPlannerRestrictionContext creates a new planner restriction
- * and a new join context, inserts it to the beginning of the
+ * context with an empty relation restriction context and an empty join and
- * plannerRestrictionContextList. Finally, the planner restriction context is
+ * a copy of the given fast path restriction context (if present). Finally,
- * inserted to the beginning of the plannerRestrictionContextList and it is returned.
+ * the planner restriction context is inserted to the beginning of the
+ * global plannerRestrictionContextList and it is returned.
  */
 static PlannerRestrictionContext *
-CreateAndPushPlannerRestrictionContext(void)
+CreateAndPushPlannerRestrictionContext(
+	FastPathRestrictionContext *fastPathRestrictionContext)
 {
 	PlannerRestrictionContext *plannerRestrictionContext =
 		palloc0(sizeof(PlannerRestrictionContext));
@@ -2427,6 +2422,21 @@ CreateAndPushPlannerRestrictionContext(void)
 	plannerRestrictionContext->fastPathRestrictionContext =
 		palloc0(sizeof(FastPathRestrictionContext));
 
+	if (fastPathRestrictionContext != NULL)
+	{
+		/* copy the given fast path restriction context */
+		FastPathRestrictionContext *plannersFastPathCtx =
+			plannerRestrictionContext->fastPathRestrictionContext;
+		plannersFastPathCtx->fastPathRouterQuery =
+			fastPathRestrictionContext->fastPathRouterQuery;
+		plannersFastPathCtx->distributionKeyValue =
+			fastPathRestrictionContext->distributionKeyValue;
+		plannersFastPathCtx->distributionKeyHasParam =
+			fastPathRestrictionContext->distributionKeyHasParam;
+		plannersFastPathCtx->delayFastPathPlanning =
+			fastPathRestrictionContext->delayFastPathPlanning;
+	}
+
 	plannerRestrictionContext->memoryContext = CurrentMemoryContext;
 
 	/* we'll apply logical AND as we add tables */

src/backend/distributed/planner/fast_path_router_planner.c

@@ -43,8 +43,10 @@
 
 #include "pg_version_constants.h"
 
+#include "distributed/citus_clauses.h"
 #include "distributed/distributed_planner.h"
 #include "distributed/insert_select_planner.h"
+#include "distributed/local_executor.h"
 #include "distributed/metadata_cache.h"
 #include "distributed/multi_physical_planner.h" /* only to use some utility functions */
 #include "distributed/multi_router_planner.h"
@@ -53,6 +55,7 @@
 #include "distributed/shardinterval_utils.h"
 
 bool EnableFastPathRouterPlanner = true;
+bool EnableLocalFastPathQueryOptimization = true;
 
 static bool ColumnAppearsMultipleTimes(Node *quals, Var *distributionKey);
 static bool DistKeyInSimpleOpExpression(Expr *clause, Var *distColumn,
@@ -61,6 +64,24 @@ static bool ConjunctionContainsColumnFilter(Node *node,
 											Var *column,
 											Node **distributionKeyValue);
 
+/*
+ * FastPathPreprocessParseTree is used to apply transformations on the parse tree
+ * that are expected by the Postgres planner. This is called on both delayed FastPath
+ * and non-delayed FastPath queries.
+ */
+void
+FastPathPreprocessParseTree(Query *parse)
+{
+	/*
+	 * Citus planner relies on some of the transformations on constant
+	 * evaluation on the parse tree.
+	 */
+	parse->targetList =
+		(List *) eval_const_expressions(NULL, (Node *) parse->targetList);
+	parse->jointree->quals =
+		(Node *) eval_const_expressions(NULL, (Node *) parse->jointree->quals);
+}
+
 
 /*
  * FastPathPlanner is intended to be used instead of standard_planner() for trivial
@@ -73,15 +94,6 @@ static bool ConjunctionContainsColumnFilter(Node *node,
 PlannedStmt *
 FastPathPlanner(Query *originalQuery, Query *parse, ParamListInfo boundParams)
 {
-	/*
-	 * Citus planner relies on some of the transformations on constant
-	 * evaluation on the parse tree.
-	 */
-	parse->targetList =
-		(List *) eval_const_expressions(NULL, (Node *) parse->targetList);
-	parse->jointree->quals =
-		(Node *) eval_const_expressions(NULL, (Node *) parse->jointree->quals);
-
 	PlannedStmt *result = GeneratePlaceHolderPlannedStmt(originalQuery);
 
 	return result;
@@ -112,9 +124,9 @@ GeneratePlaceHolderPlannedStmt(Query *parse)
 	Plan *plan = &scanNode->plan;
 #endif
 
-	Node *distKey PG_USED_FOR_ASSERTS_ONLY = NULL;
+	FastPathRestrictionContext fprCtxt PG_USED_FOR_ASSERTS_ONLY = { 0 };
 
-	Assert(FastPathRouterQuery(parse, &distKey));
+	Assert(FastPathRouterQuery(parse, &fprCtxt));
 
 	/* there is only a single relation rte */
 #if PG_VERSION_NUM >= PG_VERSION_16
@@ -150,27 +162,83 @@ GeneratePlaceHolderPlannedStmt(Query *parse)
 }
 
 
+/*
+ * InitializeFastPathContext - helper function to initialize a FastPath
+ * restriction context with the details that the FastPath code path needs.
+ */
+static void
+InitializeFastPathContext(FastPathRestrictionContext *fastPathContext,
+						  Node *distributionKeyValue,
+						  bool canAvoidDeparse,
+						  Query *query)
+{
+	Assert(fastPathContext != NULL);
+	Assert(!fastPathContext->fastPathRouterQuery);
+	Assert(!fastPathContext->delayFastPathPlanning);
+
+	/*
+	 * We're looking at a fast path query, so we can fill the
+	 * fastPathContext with relevant details.
+	 */
+	fastPathContext->fastPathRouterQuery = true;
+	if (distributionKeyValue == NULL)
+	{
+		/* nothing to record */
+	}
+	else if (IsA(distributionKeyValue, Const))
+	{
+		fastPathContext->distributionKeyValue = (Const *) distributionKeyValue;
+	}
+	else if (IsA(distributionKeyValue, Param))
+	{
+		fastPathContext->distributionKeyHasParam = true;
+	}
+
+	/*
+	 * If local execution and the fast path optimization to
+	 * avoid deparse are enabled, and it is safe to do local
+	 * execution..
+	 */
+	if (EnableLocalFastPathQueryOptimization &&
+		EnableLocalExecution &&
+		GetCurrentLocalExecutionStatus() != LOCAL_EXECUTION_DISABLED)
+	{
+		/*
+		 * .. we can delay fast path planning until we know whether
+		 * or not the shard is local. Make a final check for volatile
+		 * functions in the query tree to determine if we should delay
+		 * the fast path planning.
+		 */
+		fastPathContext->delayFastPathPlanning = canAvoidDeparse &&
+												 !FindNodeMatchingCheckFunction(
+			(Node *) query,
+			CitusIsVolatileFunction);
+	}
+}
+
+
 /*
  * FastPathRouterQuery gets a query and returns true if the query is eligible for
- * being a fast path router query.
+ * being a fast path router query. It also fills the given fastPathContext with
+ * details about the query such as the distribution key value (if available),
+ * whether the distribution key is a parameter, and the range table entry for the
+ * table being queried.
  * The requirements for the fast path query can be listed below:
  *
  *   - SELECT/UPDATE/DELETE query without CTES, sublinks-subqueries, set operations
  *   - The query should touch only a single hash distributed or reference table
  *   - The distribution with equality operator should be in the WHERE clause
  *      and it should be ANDed with any other filters. Also, the distribution
- *      key should only exists once in the WHERE clause. So basically,
+ *      key should only exist once in the WHERE clause. So basically,
  *          SELECT ... FROM dist_table WHERE dist_key = X
  *      If the filter is a const, distributionKeyValue is set
  *   - All INSERT statements (including multi-row INSERTs) as long as the commands
  *     don't have any sublinks/CTEs etc
+ *   -
  */
 bool
-FastPathRouterQuery(Query *query, Node **distributionKeyValue)
+FastPathRouterQuery(Query *query, FastPathRestrictionContext *fastPathContext)
 {
-	FromExpr *joinTree = query->jointree;
-	Node *quals = NULL;
-
 	if (!EnableFastPathRouterPlanner)
 	{
 		return false;
@@ -201,6 +269,7 @@ FastPathRouterQuery(Query *query, Node **distributionKeyValue)
 	else if (query->commandType == CMD_INSERT)
 	{
 		/* we don't need to do any further checks, all INSERTs are fast-path */
+		InitializeFastPathContext(fastPathContext, NULL, true, query);
 		return true;
 	}
 
@@ -225,6 +294,10 @@ FastPathRouterQuery(Query *query, Node **distributionKeyValue)
 		return false;
 	}
 
+	bool isFastPath = false;
+	bool canAvoidDeparse = false;
+	Node *distributionKeyValue = NULL;
+
 	/*
 	 * If the table doesn't have a distribution column, we don't need to
 	 * check anything further.
@@ -232,45 +305,62 @@ FastPathRouterQuery(Query *query, Node **distributionKeyValue)
 	Var *distributionKey = PartitionColumn(distributedTableId, 1);
 	if (!distributionKey)
 	{
-		return true;
+		/*
+		 * Local execution may avoid a deparse on single shard distributed tables or
+		 * citus local tables. We don't yet support reference tables in this code-path
+		 * because modifications on reference tables are complicated to support here.
+		 */
+		canAvoidDeparse = IsCitusTableTypeCacheEntry(cacheEntry,
+													 SINGLE_SHARD_DISTRIBUTED) ||
+						  IsCitusTableTypeCacheEntry(cacheEntry, CITUS_LOCAL_TABLE);
+		isFastPath = true;
 	}
-
+	else
-	/* WHERE clause should not be empty for distributed tables */
-	if (joinTree == NULL ||
-		(IsCitusTableTypeCacheEntry(cacheEntry, DISTRIBUTED_TABLE) && joinTree->quals ==
-		 NULL))
 	{
-		return false;
+		FromExpr *joinTree = query->jointree;
+		Node *quals = NULL;
+
+		canAvoidDeparse = IsCitusTableTypeCacheEntry(cacheEntry, DISTRIBUTED_TABLE);
+
+		if (joinTree == NULL ||
+			(joinTree->quals == NULL && canAvoidDeparse))
+		{
+			/* no quals, not a fast path query */
+			return false;
+		}
+
+		quals = joinTree->quals;
+		if (quals != NULL && IsA(quals, List))
+		{
+			quals = (Node *) make_ands_explicit((List *) quals);
+		}
+
+		/*
+		 * Distribution column must be used in a simple equality match check and it must be
+		 * place at top level conjunction operator. In simple words, we should have
+		 *	    WHERE dist_key = VALUE [AND  ....];
+		 *
+		 *	We're also not allowing any other appearances of the distribution key in the quals.
+		 *
+		 *	Overall the logic might sound fuzzy since it involves two individual checks:
+		 *	    (a) Check for top level AND operator with one side being "dist_key = const"
+		 *	    (b) Only allow single appearance of "dist_key" in the quals
+		 *
+		 *	This is to simplify both of the individual checks and omit various edge cases
+		 *	that might arise with multiple distribution keys in the quals.
+		 */
+		isFastPath = (ConjunctionContainsColumnFilter(quals, distributionKey,
+													  &distributionKeyValue) &&
+					  !ColumnAppearsMultipleTimes(quals, distributionKey));
 	}
 
-	/* convert list of expressions into expression tree for further processing */
+	if (isFastPath)
-	quals = joinTree->quals;
-	if (quals != NULL && IsA(quals, List))
 	{
-		quals = (Node *) make_ands_explicit((List *) quals);
+		InitializeFastPathContext(fastPathContext, distributionKeyValue, canAvoidDeparse,
+								  query);
 	}
 
-	/*
+	return isFastPath;
-	 * Distribution column must be used in a simple equality match check and it must be
-	 * place at top level conjunction operator. In simple words, we should have
-	 *	    WHERE dist_key = VALUE [AND  ....];
-	 *
-	 *	We're also not allowing any other appearances of the distribution key in the quals.
-	 *
-	 *	Overall the logic might sound fuzzy since it involves two individual checks:
-	 *	    (a) Check for top level AND operator with one side being "dist_key = const"
-	 *	    (b) Only allow single appearance of "dist_key" in the quals
-	 *
-	 *	This is to simplify both of the individual checks and omit various edge cases
-	 *	that might arise with multiple distribution keys in the quals.
-	 */
-	if (ConjunctionContainsColumnFilter(quals, distributionKey, distributionKeyValue) &&
-		!ColumnAppearsMultipleTimes(quals, distributionKey))
-	{
-		return true;
-	}
-
-	return false;
 }
 
 

src/backend/distributed/planner/multi_explain.c

@@ -26,6 +26,7 @@
 #include "commands/tablecmds.h"
 #include "executor/tstoreReceiver.h"
 #include "lib/stringinfo.h"
+#include "nodes/nodeFuncs.h"
 #include "nodes/plannodes.h"
 #include "nodes/primnodes.h"
 #include "nodes/print.h"
@@ -73,6 +74,7 @@
 #include "distributed/placement_connection.h"
 #include "distributed/recursive_planning.h"
 #include "distributed/remote_commands.h"
+#include "distributed/subplan_execution.h"
 #include "distributed/tuple_destination.h"
 #include "distributed/tuplestore.h"
 #include "distributed/version_compat.h"
@@ -83,6 +85,7 @@
 bool ExplainDistributedQueries = true;
 bool ExplainAllTasks = false;
 int ExplainAnalyzeSortMethod = EXPLAIN_ANALYZE_SORT_BY_TIME;
+extern MemoryContext SubPlanExplainAnalyzeContext;
 
 /*
  * If enabled, EXPLAIN ANALYZE output & other statistics of last worker task
@@ -90,6 +93,11 @@ int ExplainAnalyzeSortMethod = EXPLAIN_ANALYZE_SORT_BY_TIME;
  */
 static char *SavedExplainPlan = NULL;
 static double SavedExecutionDurationMillisec = 0.0;
+static double SavedExplainPlanNtuples = 0;
+static double SavedExplainPlanNloops = 0;
+extern SubPlanExplainOutputData *SubPlanExplainOutput;
+uint8 TotalExplainOutputCapacity = 0;
+uint8 NumTasksOutput = 0;
 
 /* struct to save explain flags */
 typedef struct
@@ -215,7 +223,8 @@ static const char * ExplainFormatStr(ExplainFormat format);
 #if PG_VERSION_NUM >= PG_VERSION_17
 static const char * ExplainSerializeStr(ExplainSerializeOption serializeOption);
 #endif
-static void ExplainWorkerPlan(PlannedStmt *plannedStmt, DestReceiver *dest,
+static void ExplainWorkerPlan(PlannedStmt *plannedStmt, DistributedSubPlan *subPlan,
+							  DestReceiver *dest,
 							  ExplainState *es,
 							  const char *queryString, ParamListInfo params,
 							  QueryEnvironment *queryEnv,
@@ -224,7 +233,9 @@ static void ExplainWorkerPlan(PlannedStmt *plannedStmt, DestReceiver *dest,
 							  const BufferUsage *bufusage,
 							  const MemoryContextCounters *mem_counters,
 #endif
-							  double *executionDurationMillisec);
+							  double *executionDurationMillisec,
+							  double *executionTuples,
+							  double *executionLoops);
 static ExplainFormat ExtractFieldExplainFormat(Datum jsonbDoc, const char *fieldName,
 											   ExplainFormat defaultValue);
 #if PG_VERSION_NUM >= PG_VERSION_17
@@ -256,7 +267,8 @@ static double elapsed_time(instr_time *starttime);
 static void ExplainPropertyBytes(const char *qlabel, int64 bytes, ExplainState *es);
 static uint64 TaskReceivedTupleData(Task *task);
 static bool ShowReceivedTupleData(CitusScanState *scanState, ExplainState *es);
-
+static bool PlanStateAnalyzeWalker(PlanState *planState, void *ctx);
+static void ExtractAnalyzeStats(DistributedSubPlan *subPlan, PlanState *planState);
 
 /* exports for SQL callable functions */
 PG_FUNCTION_INFO_V1(worker_last_saved_explain_analyze);
@@ -432,6 +444,84 @@ NonPushableMergeCommandExplainScan(CustomScanState *node, List *ancestors,
 }
 
 
+/*
+ * ExtractAnalyzeStats parses the EXPLAIN ANALYZE output of the pre-executed
+ * subplans and injects the parsed statistics into queryDesc->planstate->instrument.
+ */
+static void
+ExtractAnalyzeStats(DistributedSubPlan *subPlan, PlanState *planState)
+{
+	if (!planState)
+	{
+		return;
+	}
+
+	Instrumentation *instr = planState->instrument;
+	if (!IsA(planState, CustomScanState))
+	{
+		instr->ntuples = subPlan->ntuples;
+		instr->nloops = 1; /* subplan nodes are executed only once */
+		return;
+	}
+
+	Assert(IsA(planState, CustomScanState));
+
+	if (subPlan->numTasksOutput <= 0)
+	{
+		return;
+	}
+
+	ListCell *lc;
+	int tasksOutput = 0;
+	double tasksNtuples = 0;
+	double tasksNloops = 0;
+	memset(instr, 0, sizeof(Instrumentation));
+	DistributedPlan *newdistributedPlan =
+		((CitusScanState *) planState)->distributedPlan;
+
+	/*
+	 * Inject the earlier executed results—extracted from the workers' EXPLAIN output—
+	 * into the newly created tasks.
+	 */
+	foreach(lc, newdistributedPlan->workerJob->taskList)
+	{
+		Task *task = (Task *) lfirst(lc);
+		uint32 taskId = task->taskId;
+
+		if (tasksOutput > subPlan->numTasksOutput)
+		{
+			break;
+		}
+
+		if (!subPlan->totalExplainOutput[taskId].explainOutput)
+		{
+			continue;
+		}
+
+		/*
+		 * Now feed the earlier saved output, which will be used
+		 * by RemoteExplain() when printing tasks
+		 */
+		MemoryContext taskContext = GetMemoryChunkContext(task);
+		task->totalReceivedTupleData =
+			subPlan->totalExplainOutput[taskId].totalReceivedTupleData;
+		task->fetchedExplainAnalyzeExecutionDuration =
+			subPlan->totalExplainOutput[taskId].executionDuration;
+		task->fetchedExplainAnalyzePlan =
+			MemoryContextStrdup(taskContext,
+								subPlan->totalExplainOutput[taskId].explainOutput);
+		tasksNtuples += subPlan->totalExplainOutput[taskId].executionNtuples;
+		tasksNloops = subPlan->totalExplainOutput[taskId].executionNloops;
+
+		subPlan->totalExplainOutput[taskId].explainOutput = NULL;
+		tasksOutput++;
+	}
+
+	instr->ntuples = tasksNtuples;
+	instr->nloops = tasksNloops;
+}
+
+
 /*
  * ExplainSubPlans generates EXPLAIN output for subplans for CTEs
  * and complex subqueries. Because the planning for these queries
@@ -450,7 +540,6 @@ ExplainSubPlans(DistributedPlan *distributedPlan, ExplainState *es)
 	{
 		DistributedSubPlan *subPlan = (DistributedSubPlan *) lfirst(subPlanCell);
 		PlannedStmt *plan = subPlan->plan;
-		IntoClause *into = NULL;
 		ParamListInfo params = NULL;
 
 		/*
@@ -534,6 +623,11 @@ ExplainSubPlans(DistributedPlan *distributedPlan, ExplainState *es)
 
 		ExplainOpenGroup("PlannedStmt", "PlannedStmt", false, es);
 
+		DestReceiver *dest = None_Receiver; /* No query execution */
+		double executionDurationMillisec = 0.0;
+		double executionTuples = 0;
+		double executionLoops = 0;
+
 /* Capture memory stats on PG17+ */
 #if PG_VERSION_NUM >= PG_VERSION_17
 		if (es->memory)
@@ -541,46 +635,21 @@ ExplainSubPlans(DistributedPlan *distributedPlan, ExplainState *es)
 			MemoryContextSwitchTo(saved_ctx);
 			MemoryContextMemConsumed(planner_ctx, &mem_counters);
 		}
-#endif
 
-#if PG_VERSION_NUM >= PG_VERSION_18
+		/* Execute EXPLAIN without ANALYZE */
-		ExplainOnePlan(
+		ExplainWorkerPlan(plan, subPlan, dest, es, queryString, params, NULL,
-			plan,                            /* PlannedStmt *plannedstmt */
+						  &planduration,
-			NULL,                            /* CachedPlan *cplan */
+						  (es->buffers ? &bufusage : NULL),
-			NULL,                            /* CachedPlanSource *plansource */
+						  (es->memory ? &mem_counters : NULL),
-			0,                               /* query_index */
+						  &executionDurationMillisec,
-			into,                            /* IntoClause *into */
+						  &executionTuples,
-			es,                              /* struct ExplainState *es */
+						  &executionLoops);
-			queryString,                     /* const char *queryString */
-			params,                          /* ParamListInfo params */
-			NULL,                            /* QueryEnvironment *queryEnv */
-			&planduration,                   /* const instr_time *planduration */
-			(es->buffers ? &bufusage : NULL),/* const BufferUsage *bufusage */
-			(es->memory ? &mem_counters : NULL)  /* const MemoryContextCounters *mem_counters */
-			);
-#elif PG_VERSION_NUM >= PG_VERSION_17
-		ExplainOnePlan(
-			plan,
-			into,
-			es,
-			queryString,
-			params,
-			NULL,                           /* QueryEnvironment *queryEnv */
-			&planduration,
-			(es->buffers ? &bufusage : NULL),
-			(es->memory ? &mem_counters : NULL)
-			);
 #else
-		ExplainOnePlan(
+
-			plan,
+		/* Execute EXPLAIN without ANALYZE */
-			into,
+		ExplainWorkerPlan(plan, subPlan, dest, es, queryString, params, NULL,
-			es,
+						  &planduration, &executionDurationMillisec,
-			queryString,
+						  &executionTuples, &executionLoops);
-			params,
-			NULL,                           /* QueryEnvironment *queryEnv */
-			&planduration,
-			(es->buffers ? &bufusage : NULL)
-			);
 #endif
 
 		ExplainCloseGroup("PlannedStmt", "PlannedStmt", false, es);
@@ -1251,17 +1320,19 @@ worker_last_saved_explain_analyze(PG_FUNCTION_ARGS)
 	if (SavedExplainPlan != NULL)
 	{
 		int columnCount = tupleDescriptor->natts;
-		if (columnCount != 2)
+		if (columnCount != 4)
 		{
-			ereport(ERROR, (errmsg("expected 3 output columns in definition of "
+			ereport(ERROR, (errmsg("expected 4 output columns in definition of "
 								   "worker_last_saved_explain_analyze, but got %d",
 								   columnCount)));
 		}
 
-		bool columnNulls[2] = { false };
+		bool columnNulls[4] = { false };
-		Datum columnValues[2] = {
+		Datum columnValues[4] = {
 			CStringGetTextDatum(SavedExplainPlan),
-			Float8GetDatum(SavedExecutionDurationMillisec)
+			Float8GetDatum(SavedExecutionDurationMillisec),
+			Float8GetDatum(SavedExplainPlanNtuples),
+			Float8GetDatum(SavedExplainPlanNloops)
 		};
 
 		tuplestore_putvalues(tupleStore, tupleDescriptor, columnValues, columnNulls);
@@ -1282,6 +1353,8 @@ worker_save_query_explain_analyze(PG_FUNCTION_ARGS)
 	text *queryText = PG_GETARG_TEXT_P(0);
 	char *queryString = text_to_cstring(queryText);
 	double executionDurationMillisec = 0.0;
+	double executionTuples = 0;
+	double executionLoops = 0;
 
 	Datum explainOptions = PG_GETARG_DATUM(1);
 	ExplainState *es = NewExplainState();
@@ -1398,16 +1471,19 @@ worker_save_query_explain_analyze(PG_FUNCTION_ARGS)
 	}
 
 	/* do the actual EXPLAIN ANALYZE */
-	ExplainWorkerPlan(plan, tupleStoreDest, es, queryString, boundParams, NULL,
+	ExplainWorkerPlan(plan, NULL, tupleStoreDest, es, queryString, boundParams, NULL,
 					  &planDuration,
 					  (es->buffers ? &bufusage : NULL),
 					  (es->memory ? &mem_counters : NULL),
-					  &executionDurationMillisec);
+					  &executionDurationMillisec,
+					  &executionTuples,
+					  &executionLoops);
 #else
 
 	/* do the actual EXPLAIN ANALYZE */
-	ExplainWorkerPlan(plan, tupleStoreDest, es, queryString, boundParams, NULL,
+	ExplainWorkerPlan(plan, NULL, tupleStoreDest, es, queryString, boundParams, NULL,
-					  &planDuration, &executionDurationMillisec);
+					  &planDuration, &executionDurationMillisec,
+					  &executionTuples, &executionLoops);
 #endif
 
 	ExplainEndOutput(es);
@@ -1418,6 +1494,8 @@ worker_save_query_explain_analyze(PG_FUNCTION_ARGS)
 
 	SavedExplainPlan = pstrdup(es->str->data);
 	SavedExecutionDurationMillisec = executionDurationMillisec;
+	SavedExplainPlanNtuples = executionTuples;
+	SavedExplainPlanNloops = executionLoops;
 
 	MemoryContextSwitchTo(oldContext);
 
@@ -1606,22 +1684,7 @@ CitusExplainOneQuery(Query *query, int cursorOptions, IntoClause *into,
 	}
 #endif
 
-#if PG_VERSION_NUM >= PG_VERSION_18
+#if PG_VERSION_NUM >= PG_VERSION_17
-	ExplainOnePlan(
-		plan,                          /* PlannedStmt *plannedstmt */
-		NULL,                          /* no CachedPlan */
-		NULL,                          /* no CachedPlanSource */
-		0,                             /* query_index */
-		into,                          /* IntoClause *into */
-		es,                            /* struct ExplainState *es */
-		queryString,                   /* const char *queryString */
-		params,                        /* ParamListInfo params */
-		queryEnv,                      /* QueryEnvironment *queryEnv */
-		&planduration,                 /* const instr_time *planduration */
-		(es->buffers ? &bufusage : NULL),   /* const BufferUsage *bufusage */
-		(es->memory ? &mem_counters : NULL) /* const MemoryContextCounters *mem_counters */
-		);
-#elif PG_VERSION_NUM >= PG_VERSION_17
 
 	/* PostgreSQL 17 signature (9 args: includes mem_counters) */
 	ExplainOnePlan(
@@ -1662,11 +1725,13 @@ CreateExplainAnlyzeDestination(Task *task, TupleDestination *taskDest)
 	tupleDestination->originalTask = task;
 	tupleDestination->originalTaskDestination = taskDest;
 
-	TupleDesc lastSavedExplainAnalyzeTupDesc = CreateTemplateTupleDesc(2);
+	TupleDesc lastSavedExplainAnalyzeTupDesc = CreateTemplateTupleDesc(4);
 
 	TupleDescInitEntry(lastSavedExplainAnalyzeTupDesc, 1, "explain analyze", TEXTOID, 0,
 					   0);
 	TupleDescInitEntry(lastSavedExplainAnalyzeTupDesc, 2, "duration", FLOAT8OID, 0, 0);
+	TupleDescInitEntry(lastSavedExplainAnalyzeTupDesc, 3, "ntuples", FLOAT8OID, 0, 0);
+	TupleDescInitEntry(lastSavedExplainAnalyzeTupDesc, 4, "nloops", FLOAT8OID, 0, 0);
 
 	tupleDestination->lastSavedExplainAnalyzeTupDesc = lastSavedExplainAnalyzeTupDesc;
 
@@ -1677,6 +1742,51 @@ CreateExplainAnlyzeDestination(Task *task, TupleDestination *taskDest)
 }
 
 
+/*
+ * EnsureExplainOutputCapacity is to ensure capacity for new entries. Input
+ * parameter requiredSize is minimum number of elements needed.
+ */
+static void
+EnsureExplainOutputCapacity(int requiredSize)
+{
+	if (requiredSize < TotalExplainOutputCapacity)
+	{
+		return;
+	}
+
+	int newCapacity =
+		(TotalExplainOutputCapacity == 0) ? 32 : TotalExplainOutputCapacity * 2;
+
+	while (newCapacity <= requiredSize)
+	{
+		newCapacity *= 2;
+	}
+
+	if (SubPlanExplainOutput == NULL)
+	{
+		SubPlanExplainOutput =
+			(SubPlanExplainOutputData *) MemoryContextAllocZero(
+				SubPlanExplainAnalyzeContext,
+				newCapacity *
+				sizeof(SubPlanExplainOutputData));
+	}
+	else
+	{
+		/* Use repalloc and manually zero the new memory */
+		int oldSize = TotalExplainOutputCapacity * sizeof(SubPlanExplainOutputData);
+		int newSize = newCapacity * sizeof(SubPlanExplainOutputData);
+
+		SubPlanExplainOutput =
+			(SubPlanExplainOutputData *) repalloc(SubPlanExplainOutput, newSize);
+
+		/* Zero out the newly allocated memory */
+		MemSet((char *) SubPlanExplainOutput + oldSize, 0, newSize - oldSize);
+	}
+
+	TotalExplainOutputCapacity = newCapacity;
+}
+
+
 /*
  * ExplainAnalyzeDestPutTuple implements TupleDestination->putTuple
  * for ExplainAnalyzeDestination.
@@ -1686,6 +1796,8 @@ ExplainAnalyzeDestPutTuple(TupleDestination *self, Task *task,
 						   int placementIndex, int queryNumber,
 						   HeapTuple heapTuple, uint64 tupleLibpqSize)
 {
+	uint32 taskId = task->taskId;
+
 	ExplainAnalyzeDestination *tupleDestination = (ExplainAnalyzeDestination *) self;
 	if (queryNumber == 0)
 	{
@@ -1693,6 +1805,13 @@ ExplainAnalyzeDestPutTuple(TupleDestination *self, Task *task,
 		originalTupDest->putTuple(originalTupDest, task, placementIndex, 0, heapTuple,
 								  tupleLibpqSize);
 		tupleDestination->originalTask->totalReceivedTupleData += tupleLibpqSize;
+
+		if (SubPlanExplainAnalyzeContext)
+		{
+			EnsureExplainOutputCapacity(taskId + 1);
+			SubPlanExplainOutput[taskId].totalReceivedTupleData =
+				tupleDestination->originalTask->totalReceivedTupleData;
+		}
 	}
 	else if (queryNumber == 1)
 	{
@@ -1708,6 +1827,8 @@ ExplainAnalyzeDestPutTuple(TupleDestination *self, Task *task,
 		}
 
 		Datum executionDuration = heap_getattr(heapTuple, 2, tupDesc, &isNull);
+		Datum executionTuples = heap_getattr(heapTuple, 3, tupDesc, &isNull);
+		Datum executionLoops = heap_getattr(heapTuple, 4, tupDesc, &isNull);
 
 		if (isNull)
 		{
@@ -1717,6 +1838,8 @@ ExplainAnalyzeDestPutTuple(TupleDestination *self, Task *task,
 
 		char *fetchedExplainAnalyzePlan = TextDatumGetCString(explainAnalyze);
 		double fetchedExplainAnalyzeExecutionDuration = DatumGetFloat8(executionDuration);
+		double fetchedExplainAnalyzeTuples = DatumGetFloat8(executionTuples);
+		double fetchedExplainAnalyzeLoops = DatumGetFloat8(executionLoops);
 
 		/*
 		 * Allocate fetchedExplainAnalyzePlan in the same context as the Task, since we are
@@ -1742,6 +1865,20 @@ ExplainAnalyzeDestPutTuple(TupleDestination *self, Task *task,
 			placementIndex;
 		tupleDestination->originalTask->fetchedExplainAnalyzeExecutionDuration =
 			fetchedExplainAnalyzeExecutionDuration;
+
+		/* We should build tupleDestination in subPlan similar to the above */
+		if (SubPlanExplainAnalyzeContext)
+		{
+			EnsureExplainOutputCapacity(taskId + 1);
+			SubPlanExplainOutput[taskId].explainOutput =
+				MemoryContextStrdup(SubPlanExplainAnalyzeContext,
+									fetchedExplainAnalyzePlan);
+			SubPlanExplainOutput[taskId].executionDuration =
+				fetchedExplainAnalyzeExecutionDuration;
+			SubPlanExplainOutput[taskId].executionNtuples = fetchedExplainAnalyzeTuples;
+			SubPlanExplainOutput[taskId].executionNloops = fetchedExplainAnalyzeLoops;
+			NumTasksOutput++;
+		}
 	}
 	else
 	{
@@ -1804,7 +1941,14 @@ ExplainAnalyzeDestTupleDescForQuery(TupleDestination *self, int queryNumber)
 bool
 RequestedForExplainAnalyze(CitusScanState *node)
 {
-	return (node->customScanState.ss.ps.state->es_instrument != 0);
+	/*
+	 * When running a distributed plan—either the root plan or a subplan’s
+	 * distributed fragment—we need to know if we’re under EXPLAIN ANALYZE.
+	 * Subplans can’t receive the EXPLAIN ANALYZE flag directly, so we use
+	 * SubPlanExplainAnalyzeContext as a flag to indicate that context.
+	 */
+	return (node->customScanState.ss.ps.state->es_instrument != 0) ||
+		   (SubPlanLevel > 0 && SubPlanExplainAnalyzeContext);
 }
 
 
@@ -1963,7 +2107,8 @@ FetchPlanQueryForExplainAnalyze(const char *queryString, ParamListInfo params)
 	}
 
 	appendStringInfoString(fetchQuery,
-						   "SELECT explain_analyze_output, execution_duration "
+						   "SELECT explain_analyze_output, execution_duration, "
+						   "execution_ntuples, execution_nloops "
 						   "FROM worker_last_saved_explain_analyze()");
 
 	return fetchQuery->data;
@@ -2107,22 +2252,7 @@ ExplainOneQuery(Query *query, int cursorOptions,
 		}
 #endif
 
-#if PG_VERSION_NUM >= PG_VERSION_18
+#if PG_VERSION_NUM >= PG_VERSION_17
-		ExplainOnePlan(
-			plan,                 /* PlannedStmt *plannedstmt */
-			NULL,                 /* CachedPlan *cplan */
-			NULL,                 /* CachedPlanSource *plansource */
-			0,                    /* query_index */
-			into,                 /* IntoClause *into */
-			es,                   /* struct ExplainState *es */
-			queryString,          /* const char *queryString */
-			params,               /* ParamListInfo params */
-			queryEnv,             /* QueryEnvironment *queryEnv */
-			&planduration,        /* const instr_time *planduration */
-			(es->buffers  ? &bufusage    : NULL),
-			(es->memory   ? &mem_counters: NULL)
-		);
-#elif PG_VERSION_NUM >= PG_VERSION_17
 		ExplainOnePlan(
 			plan,
 			into,
@@ -2146,11 +2276,24 @@ ExplainOneQuery(Query *query, int cursorOptions,
 			(es->buffers ? &bufusage : NULL)
 		);
 #endif
-
 	}
 }
 
 
+/*
+ * PlanStateAnalyzeWalker Tree walker callback that visits each PlanState node in the
+ * plan tree and extracts analyze statistics from CustomScanState tasks using
+ * ExtractAnalyzeStats. Always returns false to recurse into all children.
+ */
+static bool
+PlanStateAnalyzeWalker(PlanState *planState, void *ctx)
+{
+	DistributedSubPlan *subplan = (DistributedSubPlan *) ctx;
+	ExtractAnalyzeStats(subplan, planState);
+	return false;
+}
+
+
 /*
  * ExplainWorkerPlan produces explain output into es. If es->analyze, it also executes
  * the given plannedStmt and sends the results to dest. It puts total time to execute in
@@ -2165,20 +2308,25 @@ ExplainOneQuery(Query *query, int cursorOptions,
  * destination.
  */
 static void
-ExplainWorkerPlan(PlannedStmt *plannedstmt, DestReceiver *dest, ExplainState *es,
+ExplainWorkerPlan(PlannedStmt *plannedstmt, DistributedSubPlan *subPlan, DestReceiver *dest, ExplainState *es,
 				  const char *queryString, ParamListInfo params, QueryEnvironment *queryEnv,
 				  const instr_time *planduration,
 #if PG_VERSION_NUM >= PG_VERSION_17
 				  const BufferUsage *bufusage,
 			      const MemoryContextCounters *mem_counters,
 #endif
-				  double *executionDurationMillisec)
+				  double *executionDurationMillisec,
+				  double *executionTuples,
+				  double *executionLoops)
 {
 	QueryDesc  *queryDesc;
 	instr_time	starttime;
 	double		totaltime = 0;
 	int			eflags;
 	int			instrument_option = 0;
+	/* Sub-plan already executed; skipping execution */
+	bool executeQuery = (es->analyze && !subPlan);
+	bool executeSubplan = (es->analyze && subPlan);
 
 	Assert(plannedstmt->commandType != CMD_UTILITY);
 
@@ -2208,19 +2356,6 @@ ExplainWorkerPlan(PlannedStmt *plannedstmt, DestReceiver *dest, ExplainState *es
 	UpdateActiveSnapshotCommandId();
 
 	/* Create a QueryDesc for the query */
-	#if PG_VERSION_NUM >= PG_VERSION_18
-	queryDesc = CreateQueryDesc(
-		plannedstmt,    /* PlannedStmt *plannedstmt */
-		NULL,           /* CachedPlan *cplan (none) */
-		queryString,    /* const char *sourceText */
-		GetActiveSnapshot(),   /* Snapshot snapshot */
-		InvalidSnapshot,       /* Snapshot crosscheck_snapshot */
-		dest,           /* DestReceiver *dest */
-		params,         /* ParamListInfo params */
-		queryEnv,       /* QueryEnvironment *queryEnv */
-		instrument_option /* int instrument_options */
-	);
-	#else
 	queryDesc = CreateQueryDesc(
 		plannedstmt,    /* PlannedStmt *plannedstmt */
 		queryString,    /* const char *sourceText */
@@ -2231,10 +2366,9 @@ ExplainWorkerPlan(PlannedStmt *plannedstmt, DestReceiver *dest, ExplainState *es
 		queryEnv,       /* QueryEnvironment *queryEnv */
 		instrument_option /* int instrument_options */
 	);
-	#endif
 
 	/* Select execution options */
-	if (es->analyze)
+	if (executeQuery)
 		eflags = 0;				/* default run-to-completion flags */
 	else
 		eflags = EXEC_FLAG_EXPLAIN_ONLY;
@@ -2243,7 +2377,7 @@ ExplainWorkerPlan(PlannedStmt *plannedstmt, DestReceiver *dest, ExplainState *es
 	ExecutorStart(queryDesc, eflags);
 
 	/* Execute the plan for statistics if asked for */
-	if (es->analyze)
+	if (executeQuery)
 	{
 		ScanDirection dir = ForwardScanDirection;
 
@@ -2266,6 +2400,12 @@ ExplainWorkerPlan(PlannedStmt *plannedstmt, DestReceiver *dest, ExplainState *es
 
 	ExplainOpenGroup("Query", NULL, true, es);
 
+	if (executeSubplan)
+	{
+		ExtractAnalyzeStats(subPlan, queryDesc->planstate);
+		planstate_tree_walker(queryDesc->planstate, PlanStateAnalyzeWalker, (void *) subPlan);
+	}
+
 	/* Create textual dump of plan tree */
 	ExplainPrintPlan(es, queryDesc);
 
@@ -2338,6 +2478,13 @@ ExplainWorkerPlan(PlannedStmt *plannedstmt, DestReceiver *dest, ExplainState *es
 	 */
 	INSTR_TIME_SET_CURRENT(starttime);
 
+	if (executeQuery)
+	{
+		Instrumentation *instr = queryDesc->planstate->instrument;
+		*executionTuples = instr->ntuples;
+		*executionLoops = instr->nloops;
+	}
+
 	ExecutorEnd(queryDesc);
 
 	FreeQueryDesc(queryDesc);
@@ -2345,7 +2492,7 @@ ExplainWorkerPlan(PlannedStmt *plannedstmt, DestReceiver *dest, ExplainState *es
 	PopActiveSnapshot();
 
 	/* We need a CCI just in case query expanded to multiple plans */
-	if (es->analyze)
+	if (executeQuery)
 		CommandCounterIncrement();
 
 	totaltime += elapsed_time(&starttime);

src/backend/distributed/planner/multi_router_planner.c

@@ -16,6 +16,8 @@
 #include "postgres.h"
 
 #include "access/stratnum.h"
+#include "access/tupdesc.h"
+#include "access/tupdesc_details.h"
 #include "access/xact.h"
 #include "catalog/pg_opfamily.h"
 #include "catalog/pg_proc.h"
@@ -34,6 +36,7 @@
 #include "optimizer/pathnode.h"
 #include "optimizer/paths.h"
 #include "optimizer/planmain.h"
+#include "optimizer/planner.h"
 #include "optimizer/restrictinfo.h"
 #include "parser/parse_oper.h"
 #include "parser/parsetree.h"
@@ -81,6 +84,7 @@
 #include "distributed/relay_utility.h"
 #include "distributed/resource_lock.h"
 #include "distributed/shard_pruning.h"
+#include "distributed/shard_utils.h"
 #include "distributed/shardinterval_utils.h"
 
 /* intermediate value for INSERT processing */
@@ -164,7 +168,7 @@ static List * SingleShardTaskList(Query *query, uint64 jobId,
 								  List *relationShardList, List *placementList,
 								  uint64 shardId, bool parametersInQueryResolved,
 								  bool isLocalTableModification, Const *partitionKeyValue,
-								  int colocationId);
+								  int colocationId, bool delayedFastPath);
 static bool RowLocksOnRelations(Node *node, List **rtiLockList);
 static void ReorderTaskPlacementsByTaskAssignmentPolicy(Job *job,
 														TaskAssignmentPolicyType
@@ -173,7 +177,7 @@ static void ReorderTaskPlacementsByTaskAssignmentPolicy(Job *job,
 static bool ModifiesLocalTableWithRemoteCitusLocalTable(List *rangeTableList);
 static DeferredErrorMessage * DeferErrorIfUnsupportedLocalTableJoin(List *rangeTableList);
 static bool IsLocallyAccessibleCitusLocalTable(Oid relationId);
-
+static bool ConvertToQueryOnShard(Query *query, Oid relationID, Oid shardRelationId);
 
 /*
  * CreateRouterPlan attempts to create a router executor plan for the given
@@ -1940,7 +1944,9 @@ RouterJob(Query *originalQuery, PlannerRestrictionContext *plannerRestrictionCon
 	{
 		GenerateSingleShardRouterTaskList(job, relationShardList,
 										  placementList, shardId,
-										  isLocalTableModification);
+										  isLocalTableModification,
+										  fastPathRestrictionContext->
+										  delayFastPathPlanning);
 	}
 
 	job->requiresCoordinatorEvaluation = requiresCoordinatorEvaluation;
@@ -1948,6 +1954,262 @@ RouterJob(Query *originalQuery, PlannerRestrictionContext *plannerRestrictionCon
 }
 
 
+/*
+ * CheckAttributesMatch checks if the attributes of the Citus table and the shard
+ * table match.
+ *
+ * It is used to ensure that the shard table has the same schema as the Citus
+ * table before replacing the Citus table OID with the shard table OID in the
+ * parse tree we (Citus planner) recieved from Postgres.
+ */
+static
+bool
+CheckAttributesMatch(Oid citusTableId, Oid shardTableId)
+{
+	bool same_schema = false;
+	Relation citusRelation = RelationIdGetRelation(citusTableId);
+	Relation shardRelation = RelationIdGetRelation(shardTableId);
+
+	if (RelationIsValid(citusRelation) && RelationIsValid(shardRelation))
+	{
+		TupleDesc citusTupDesc = citusRelation->rd_att;
+		TupleDesc shardTupDesc = shardRelation->rd_att;
+
+		if (citusTupDesc->natts == shardTupDesc->natts)
+		{
+			/*
+			 * Do an attribute-by-attribute comparison. This is borrowed from
+			 * the Postgres function equalTupleDescs(), which we cannot use
+			 * because the citus table and shard table have different composite
+			 * types.
+			 */
+			same_schema = true;
+			for (int i = 0; i < citusTupDesc->natts && same_schema; i++)
+			{
+				Form_pg_attribute attr1 = TupleDescAttr(citusTupDesc, i);
+				Form_pg_attribute attr2 = TupleDescAttr(shardTupDesc, i);
+
+				if (strcmp(NameStr(attr1->attname), NameStr(attr2->attname)) != 0)
+				{
+					same_schema = false;
+				}
+				if (attr1->atttypid != attr2->atttypid)
+				{
+					same_schema = false;
+				}
+				if (attr1->atttypmod != attr2->atttypmod)
+				{
+					same_schema = false;
+				}
+				if (attr1->attcollation != attr2->attcollation)
+				{
+					same_schema = false;
+				}
+
+				/* Record types derived from tables could have dropped fields. */
+				if (attr1->attisdropped != attr2->attisdropped)
+				{
+					same_schema = false;
+				}
+			}
+		}
+	}
+
+	RelationClose(citusRelation);
+	RelationClose(shardRelation);
+	return same_schema;
+}
+
+
+/*
+ * CheckAndBuildDelayedFastPathPlan() - if the query being planned is a fast
+ * path query, not marked for deferred pruning and the placement for the task
+ * is not a dummy placement then if the placement is local to this node we can
+ * take a shortcut of replacing the OID of the citus table with the OID of the
+ * shard in the query tree and plan that directly, instead of deparsing the
+ * parse tree to a SQL query on the shard and parsing and planning that in
+ * the local executor. Instead, the local executor can use the plan created
+ * here.
+ */
+void
+CheckAndBuildDelayedFastPathPlan(DistributedPlanningContext *planContext,
+								 DistributedPlan *plan)
+{
+	FastPathRestrictionContext *fastPathContext =
+		planContext->plannerRestrictionContext->fastPathRestrictionContext;
+
+	if (!fastPathContext->delayFastPathPlanning)
+	{
+		return;
+	}
+
+	Job *job = plan->workerJob;
+	Assert(job != NULL);
+
+	if (job->deferredPruning)
+	{
+		/* Execution time pruning => don't know which shard at this point */
+		planContext->plan = FastPathPlanner(planContext->originalQuery,
+											planContext->query,
+											planContext->boundParams);
+		return;
+	}
+
+	List *tasks = job->taskList;
+	Assert(list_length(tasks) == 1);
+	Task *task = (Task *) linitial(tasks);
+	List *placements = task->taskPlacementList;
+	int32 localGroupId = GetLocalGroupId();
+	ShardPlacement *primaryPlacement = (ShardPlacement *) linitial(placements);
+
+	bool isLocalExecution = !IsDummyPlacement(primaryPlacement) &&
+							(primaryPlacement->groupId == localGroupId);
+	bool canBuildLocalPlan = true;
+
+	if (isLocalExecution)
+	{
+		List *relationShards = task->relationShardList;
+		Assert(list_length(relationShards) == 1);
+		RelationShard *relationShard = (RelationShard *) linitial(relationShards);
+		Assert(relationShard->shardId == primaryPlacement->shardId);
+
+		/*
+		 * Today FastPathRouterQuery() doesn't set delayFastPathPlanning to true for
+		 * reference tables. We should be looking at 1 placement, or their replication
+		 * factor.
+		 */
+		Assert(list_length(placements) == 1 || list_length(placements) ==
+			   TableShardReplicationFactor(relationShard->relationId));
+
+		canBuildLocalPlan = ConvertToQueryOnShard(planContext->query,
+												  relationShard->relationId,
+												  relationShard->shardId);
+		if (canBuildLocalPlan)
+		{
+			/* Plan the query with the new shard relation id */
+			planContext->plan = standard_planner(planContext->query, NULL,
+												 planContext->cursorOptions,
+												 planContext->boundParams);
+			SetTaskQueryPlan(task, job->jobQuery, planContext->plan);
+
+			ereport(DEBUG2, (errmsg(
+								 "Fast-path router query: created local execution plan "
+								 "to avoid deparse and compile of shard query")));
+			return;
+		}
+	}
+
+	/*
+	 * Either the shard is not local to this node, or it was not safe to replace
+	 * the OIDs in the parse tree; in any case we fall back to generating the shard
+	 * query and compiling that.
+	 */
+	Assert(!isLocalExecution || (isLocalExecution && !canBuildLocalPlan));
+
+	/* Fall back to fast path planner and generating SQL query on the shard */
+	planContext->plan = FastPathPlanner(planContext->originalQuery,
+										planContext->query,
+										planContext->boundParams);
+	UpdateRelationToShardNames((Node *) job->jobQuery, task->relationShardList);
+	SetTaskQueryIfShouldLazyDeparse(task, job->jobQuery);
+}
+
+
+/*
+ * ConvertToQueryOnShard() converts the given query on a citus table (identified by
+ * citusTableOid) to a query on a shard (identified by shardId).
+ *
+ * The function assumes that the query is a "fast path" query - it has only one
+ * RangeTblEntry and one RTEPermissionInfo.
+ *
+ * It acquires the same lock on the shard that was acquired on the citus table
+ * by the Postgres parser. It checks that the attribute numbers and metadata of
+ * the shard table and citus table are identical - otherwise it is not safe
+ * to proceed with this shortcut. Assuming the attributes do match, the actual
+ * conversion involves changing the target list entries that reference the
+ * citus table's oid to reference the shard's relation id instead. Finally,
+ * it changes the RangeTblEntry's relid to the shard's relation id and (PG16+)
+ * changes the RTEPermissionInfo's relid to the shard's relation id also.
+ * At this point the Query is ready for the postgres planner.
+ */
+static bool
+ConvertToQueryOnShard(Query *query, Oid citusTableOid, Oid shardId)
+{
+	Assert(list_length(query->rtable) == 1);
+	RangeTblEntry *citusTableRte = (RangeTblEntry *) linitial(query->rtable);
+	Assert(citusTableRte->relid == citusTableOid);
+
+	const char *citusTableName = get_rel_name(citusTableOid);
+	Assert(citusTableName != NULL);
+
+	/* construct shard relation name */
+	char *shardRelationName = pstrdup(citusTableName);
+	AppendShardIdToName(&shardRelationName, shardId);
+
+	/* construct the schema name */
+	char *schemaName = get_namespace_name(get_rel_namespace(citusTableOid));
+
+	/* now construct a range variable for the shard */
+	RangeVar shardRangeVar = {
+		.relname = shardRelationName,
+		.schemaname = schemaName,
+		.inh = citusTableRte->inh,
+		.relpersistence = RELPERSISTENCE_PERMANENT,
+	};
+
+	/* Must apply the same lock to the shard that was applied to the citus table */
+	Oid shardRelationId = RangeVarGetRelidExtended(&shardRangeVar,
+												   citusTableRte->rellockmode,
+												   0, NULL, NULL);
+
+	/* Verify that the attributes of citus table and shard table match */
+	if (!CheckAttributesMatch(citusTableOid, shardRelationId))
+	{
+		/* There is a difference between the attributes of the citus
+		 * table and the shard table. This can happen if there is a DROP
+		 * COLUMN on the citus table. In this case, we cannot
+		 * convert the query to a shard query, so clean up and return.
+		 */
+		UnlockRelationOid(shardRelationId, citusTableRte->rellockmode);
+		ereport(DEBUG2, (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+						 errmsg(
+							 "Router planner fast path cannot modify parse tree for local execution: shard table \"%s.%s\" does not match the "
+							 "distributed table \"%s.%s\"",
+							 schemaName, shardRelationName, schemaName,
+							 citusTableName)));
+		pfree(shardRelationName);
+		pfree(schemaName);
+
+		return false;
+	}
+
+	/* Change the target list entries that reference the original citus table's relation id */
+	ListCell *lc = NULL;
+	foreach(lc, query->targetList)
+	{
+		TargetEntry *targetEntry = (TargetEntry *) lfirst(lc);
+		if (targetEntry->resorigtbl == citusTableOid)
+		{
+			targetEntry->resorigtbl = shardRelationId;
+		}
+	}
+
+	/* Change the range table entry's oid to that of the shard's */
+	Assert(shardRelationId != InvalidOid);
+	citusTableRte->relid = shardRelationId;
+
+#if PG_VERSION_NUM >= PG_VERSION_16
+
+	/* Change the range table permission oid to that of the shard's (PG16+) */
+	Assert(list_length(query->rteperminfos) == 1);
+	RTEPermissionInfo *rtePermInfo = (RTEPermissionInfo *) linitial(query->rteperminfos);
+	rtePermInfo->relid = shardRelationId;
+#endif
+
+	return true;
+}
+
+
 /*
  * GenerateSingleShardRouterTaskList is a wrapper around other corresponding task
  * list generation functions specific to single shard selects and modifications.
@@ -1957,7 +2219,7 @@ RouterJob(Query *originalQuery, PlannerRestrictionContext *plannerRestrictionCon
 void
 GenerateSingleShardRouterTaskList(Job *job, List *relationShardList,
 								  List *placementList, uint64 shardId, bool
-								  isLocalTableModification)
+								  isLocalTableModification, bool delayedFastPath)
 {
 	Query *originalQuery = job->jobQuery;
 
@@ -1970,7 +2232,8 @@ GenerateSingleShardRouterTaskList(Job *job, List *relationShardList,
 											shardId,
 											job->parametersInJobQueryResolved,
 											isLocalTableModification,
-											job->partitionKeyValue, job->colocationId);
+											job->partitionKeyValue, job->colocationId,
+											delayedFastPath);
 
 		/*
 		 * Queries to reference tables, or distributed tables with multiple replica's have
@@ -2001,7 +2264,8 @@ GenerateSingleShardRouterTaskList(Job *job, List *relationShardList,
 											shardId,
 											job->parametersInJobQueryResolved,
 											isLocalTableModification,
-											job->partitionKeyValue, job->colocationId);
+											job->partitionKeyValue, job->colocationId,
+											delayedFastPath);
 	}
 }
 
@@ -2096,7 +2360,7 @@ SingleShardTaskList(Query *query, uint64 jobId, List *relationShardList,
 					List *placementList, uint64 shardId,
 					bool parametersInQueryResolved,
 					bool isLocalTableModification, Const *partitionKeyValue,
-					int colocationId)
+					int colocationId, bool delayedFastPath)
 {
 	TaskType taskType = READ_TASK;
 	char replicationModel = 0;
@@ -2168,7 +2432,10 @@ SingleShardTaskList(Query *query, uint64 jobId, List *relationShardList,
 	task->taskPlacementList = placementList;
 	task->partitionKeyValue = partitionKeyValue;
 	task->colocationId = colocationId;
-	SetTaskQueryIfShouldLazyDeparse(task, query);
+	if (!delayedFastPath)
+	{
+		SetTaskQueryIfShouldLazyDeparse(task, query);
+	}
 	task->anchorShardId = shardId;
 	task->jobId = jobId;
 	task->relationShardList = relationShardList;
@@ -2449,10 +2716,15 @@ PlanRouterQuery(Query *originalQuery,
 
 	/*
 	 * If this is an UPDATE or DELETE query which requires coordinator evaluation,
-	 * don't try update shard names, and postpone that to execution phase.
+	 * don't try update shard names, and postpone that to execution phase. Also, if
+	 * this is a delayed fast path query, we don't update the shard names
+	 * either, as the shard names will be updated in the fast path query planner.
 	 */
 	bool isUpdateOrDelete = UpdateOrDeleteOrMergeQuery(originalQuery);
-	if (!(isUpdateOrDelete && RequiresCoordinatorEvaluation(originalQuery)))
+	bool delayedFastPath =
+		plannerRestrictionContext->fastPathRestrictionContext->delayFastPathPlanning;
+	if (!(isUpdateOrDelete && RequiresCoordinatorEvaluation(originalQuery)) &&
+		!delayedFastPath)
 	{
 		UpdateRelationToShardNames((Node *) originalQuery, *relationShardList);
 	}

src/backend/distributed/planner/relation_restriction_equivalence.c

@@ -171,6 +171,14 @@ static bool FindQueryContainingRTEIdentityInternal(Node *node,
 
 static int ParentCountPriorToAppendRel(List *appendRelList, AppendRelInfo *appendRelInfo);
 
+static bool PartitionColumnSelectedForOuterJoin(Query *query,
+												RelationRestrictionContext *
+												restrictionContext,
+												JoinRestrictionContext *
+												joinRestrictionContext);
+
+static bool PartitionColumnIsInTargetList(Query *query, JoinRestriction *joinRestriction,
+										  RelationRestrictionContext *restrictionContext);
 
 /*
  * AllDistributionKeysInQueryAreEqual returns true if either
@@ -391,6 +399,80 @@ SafeToPushdownUnionSubquery(Query *originalQuery,
 		return false;
 	}
 
+	if (!PartitionColumnSelectedForOuterJoin(originalQuery,
+											 restrictionContext,
+											 joinRestrictionContext))
+	{
+		/* outer join does not select partition column of outer relation */
+		return false;
+	}
+	return true;
+}
+
+
+/*
+ * PartitionColumnSelectedForOuterJoin checks whether the partition column of
+ * the outer relation is selected in the target list of the query.
+ *
+ * If there is no outer join, it returns true.
+ */
+static bool
+PartitionColumnSelectedForOuterJoin(Query *query,
+									RelationRestrictionContext *restrictionContext,
+									JoinRestrictionContext *joinRestrictionContext)
+{
+	ListCell *joinRestrictionCell;
+	foreach(joinRestrictionCell, joinRestrictionContext->joinRestrictionList)
+	{
+		JoinRestriction *joinRestriction = (JoinRestriction *) lfirst(
+			joinRestrictionCell);
+
+		/* Restriction context includes alternative plans, sufficient to check for left joins.*/
+		if (joinRestriction->joinType != JOIN_LEFT)
+		{
+			continue;
+		}
+
+		if (!PartitionColumnIsInTargetList(query, joinRestriction, restrictionContext))
+		{
+			/* outer join does not select partition column of outer relation */
+			return false;
+		}
+	}
+
+	return true;
+}
+
+
+/*
+ * PartitionColumnIsInTargetList checks whether the partition column of
+ * the given relation is included in the target list of the query.
+ */
+static bool
+PartitionColumnIsInTargetList(Query *query, JoinRestriction *joinRestriction,
+							  RelationRestrictionContext *restrictionContext)
+{
+	Relids relids = joinRestriction->outerrelRelids;
+	int relationId = -1;
+	Index partitionKeyIndex = InvalidAttrNumber;
+	while ((relationId = bms_next_member(relids, relationId)) >= 0)
+	{
+		RangeTblEntry *rte = joinRestriction->plannerInfo->simple_rte_array[relationId];
+		if (rte->rtekind != RTE_RELATION)
+		{
+			/* skip if it is not a relation */
+			continue;
+		}
+		int targetRTEIndex = GetRTEIdentity(rte);
+		PartitionKeyForRTEIdentityInQuery(query, targetRTEIndex,
+										  &partitionKeyIndex);
+		if (partitionKeyIndex == 0)
+		{
+			/* partition key is not in the target list */
+			return false;
+		}
+	}
+
 	return true;
 }
 

src/backend/distributed/shared_library_init.c

@@ -212,6 +212,7 @@ static const char * MaxSharedPoolSizeGucShowHook(void);
 static const char * LocalPoolSizeGucShowHook(void);
 static bool StatisticsCollectionGucCheckHook(bool *newval, void **extra, GucSource
 											 source);
+static bool WarnIfLocalExecutionDisabled(bool *newval, void **extra, GucSource source);
 static void CitusAuthHook(Port *port, int status);
 static bool IsSuperuser(char *userName);
 static void AdjustDynamicLibraryPathForCdcDecoders(void);
@@ -385,51 +386,29 @@ static const struct config_enum_entry metadata_sync_mode_options[] = {
 
 
 /*----------------------------------------------------------------------*
-* On PG 18+ the hook signatures changed; we wrap the old Citus handlers
+* On PG 18+ the hook signature changed; we wrap the old Citus handler
-* in fresh functions that match the new typedefs exactly.
+* in a fresh function that matches the new typedef exactly.
 *----------------------------------------------------------------------*/
-#if PG_VERSION_NUM >= PG_VERSION_18
-static bool
-citus_executor_start_adapter(QueryDesc *queryDesc, int eflags)
-{
-	/* PG18+ expects a bool return */
-	CitusExecutorStart(queryDesc, eflags);
-	return true;
-}
-
-
 static void
 citus_executor_run_adapter(QueryDesc *queryDesc,
 						   ScanDirection direction,
-						   uint64 count)
+						   uint64 count
-{
+#if PG_VERSION_NUM < PG_VERSION_18
-	/* PG18+ has no run_once flag
+						   , bool run_once
-	 * call the original Citus hook (which still expects the old 4-arg form) */
-	CitusExecutorRun(queryDesc, direction, count, true);
-}
-
-
-#else
-
-/* PG15–17: adapter signatures must match the *old* typedefs */
-static void
-citus_executor_start_adapter(QueryDesc *queryDesc, int eflags)
-{
-	CitusExecutorStart(queryDesc, eflags);
-}
-
-
-static void
-citus_executor_run_adapter(QueryDesc *queryDesc,
-						   ScanDirection direction,
-						   uint64 count,
-						   bool run_once)
-{
-	CitusExecutorRun(queryDesc, direction, count, run_once);
-}
-
-
 #endif
+						   )
+{
+	/* PG18+ has no run_once flag */
+	CitusExecutorRun(queryDesc,
+					 direction,
+					 count,
+#if PG_VERSION_NUM >= PG_VERSION_18
+					 true
+#else
+					 run_once
+#endif
+					 );
+}
 
 
 /* shared library initialization function */
@@ -506,7 +485,7 @@ _PG_init(void)
 	set_rel_pathlist_hook = multi_relation_restriction_hook;
 	get_relation_info_hook = multi_get_relation_info_hook;
 	set_join_pathlist_hook = multi_join_restriction_hook;
-	ExecutorStart_hook = citus_executor_start_adapter;
+	ExecutorStart_hook = CitusExecutorStart;
 	ExecutorRun_hook = citus_executor_run_adapter;
 	ExplainOneQuery_hook = CitusExplainOneQuery;
 	prev_ExecutorEnd = ExecutorEnd_hook;
@@ -1426,6 +1405,17 @@ RegisterCitusConfigVariables(void)
 		GUC_STANDARD,
 		NULL, NULL, NULL);
 
+	DefineCustomBoolVariable(
+		"citus.enable_local_fast_path_query_optimization",
+		gettext_noop("Enables the planner to avoid a query deparse and planning if "
+					 "the shard is local to the current node."),
+		NULL,
+		&EnableLocalFastPathQueryOptimization,
+		true,
+		PGC_USERSET,
+		GUC_NO_SHOW_ALL | GUC_NOT_IN_SAMPLE,
+		WarnIfLocalExecutionDisabled, NULL, NULL);
+
 	DefineCustomBoolVariable(
 		"citus.enable_local_reference_table_foreign_keys",
 		gettext_noop("Enables foreign keys from/to local tables"),
@@ -2851,6 +2841,26 @@ WarnIfDeprecatedExecutorUsed(int *newval, void **extra, GucSource source)
 }
 
 
+/*
+ * WarnIfLocalExecutionDisabled is used to emit a warning message when
+ * enabling citus.enable_local_fast_path_query_optimization if
+ * citus.enable_local_execution was disabled.
+ */
+static bool
+WarnIfLocalExecutionDisabled(bool *newval, void **extra, GucSource source)
+{
+	if (*newval == true && EnableLocalExecution == false)
+	{
+		ereport(WARNING, (errcode(ERRCODE_INVALID_PARAMETER_VALUE),
+						  errmsg(
+							  "citus.enable_local_execution must be set in order for "
+							  "citus.enable_local_fast_path_query_optimization to be effective.")));
+	}
+
+	return true;
+}
+
+
 /*
  * NoticeIfSubqueryPushdownEnabled prints a notice when a user sets
  * citus.subquery_pushdown to ON. It doesn't print the notice if the

src/backend/distributed/sql/citus--13.1-1--13.2-1.sql

@@ -1,2 +1,3 @@
 -- citus--13.1-1--13.2-1
 -- bump version to 13.2-1
+#include "udfs/worker_last_saved_explain_analyze/13.2-1.sql"

src/backend/distributed/sql/downgrades/citus--13.2-1--13.1-1.sql

@@ -1,2 +1,5 @@
 -- citus--13.2-1--13.1-1
 -- downgrade version to 13.1-1
+
+DROP FUNCTION IF EXISTS pg_catalog.worker_last_saved_explain_analyze();
+#include "../udfs/worker_last_saved_explain_analyze/9.4-1.sql"

src/backend/distributed/sql/udfs/worker_last_saved_explain_analyze/13.2-1.sql

@@ -0,0 +1,10 @@
+
+DROP FUNCTION pg_catalog.worker_last_saved_explain_analyze();
+
+CREATE OR REPLACE FUNCTION pg_catalog.worker_last_saved_explain_analyze()
+    RETURNS TABLE(explain_analyze_output TEXT, execution_duration DOUBLE PRECISION,
+        execution_ntuples DOUBLE PRECISION, execution_nloops DOUBLE PRECISION)
+    LANGUAGE C STRICT
+    AS 'citus';
+COMMENT ON FUNCTION pg_catalog.worker_last_saved_explain_analyze() IS
+    'Returns the saved explain analyze output for the last run query';

src/backend/distributed/sql/udfs/worker_last_saved_explain_analyze/latest.sql

@@ -1,6 +1,9 @@
 
+DROP FUNCTION pg_catalog.worker_last_saved_explain_analyze();
+
 CREATE OR REPLACE FUNCTION pg_catalog.worker_last_saved_explain_analyze()
-    RETURNS TABLE(explain_analyze_output TEXT, execution_duration DOUBLE PRECISION)
+    RETURNS TABLE(explain_analyze_output TEXT, execution_duration DOUBLE PRECISION,
+        execution_ntuples DOUBLE PRECISION, execution_nloops DOUBLE PRECISION)
     LANGUAGE C STRICT
     AS 'citus';
 COMMENT ON FUNCTION pg_catalog.worker_last_saved_explain_analyze() IS

src/backend/distributed/transaction/transaction_recovery.c

@@ -106,7 +106,7 @@ LogTransactionRecord(int32 groupId, char *transactionName, FullTransactionId out
 	TupleDesc tupleDescriptor = RelationGetDescr(pgDistTransaction);
 	HeapTuple heapTuple = heap_form_tuple(tupleDescriptor, values, isNulls);
 
-	CatalogTupleInsert(pgDistTransaction, heapTuple);
+	CATALOG_INSERT_WITH_SNAPSHOT(pgDistTransaction, heapTuple);
 
 	CommandCounterIncrement();
 

src/backend/distributed/utils/background_jobs.c

@@ -1907,20 +1907,6 @@ ExecuteSqlString(const char *sql)
 		/* Don't display the portal in pg_cursors */
 		portal->visible = false;
 
-		#if PG_VERSION_NUM >= PG_VERSION_18
-
-		/* PG18+ added a seventh “plansource” argument */
-		PortalDefineQuery(
-			portal,
-			NULL,             /* no prepared‐stmt name */
-			sql,              /* the query text */
-			commandTag,       /* the CommandTag */
-			plantree_list,    /* List of PlannedStmt* */
-			NULL,             /* no CachedPlan */
-			NULL              /* no CachedPlanSource */
-			);
-	#else
-
 		/* PG17-: six‐arg signature */
 		PortalDefineQuery(
 			portal,
@@ -1930,7 +1916,6 @@ ExecuteSqlString(const char *sql)
 			plantree_list,    /* List of PlannedStmt* */
 			NULL              /* no CachedPlan */
 			);
-	#endif
 
 		PortalStart(portal, NULL, 0, InvalidSnapshot);
 		int16 format[] = { 1 };

src/backend/distributed/utils/citus_copyfuncs.c

@@ -147,6 +147,31 @@ CopyNodeDistributedSubPlan(COPYFUNC_ARGS)
 
 	COPY_SCALAR_FIELD(subPlanId);
 	COPY_NODE_FIELD(plan);
+	COPY_SCALAR_FIELD(bytesSentPerWorker);
+	COPY_SCALAR_FIELD(remoteWorkerCount);
+	COPY_SCALAR_FIELD(durationMillisecs);
+	COPY_SCALAR_FIELD(writeLocalFile);
+
+	if (newnode->totalExplainOutput)
+	{
+		MemSet(newnode->totalExplainOutput, 0, sizeof(newnode->totalExplainOutput));
+	}
+
+	/* copy each SubPlanExplainOutput element */
+	for (int i = 0; i < from->numTasksOutput; i++)
+	{
+		/* copy the explainOutput string pointer */
+		COPY_STRING_FIELD(totalExplainOutput[i].explainOutput);
+
+		/* copy the executionDuration (double) */
+		COPY_SCALAR_FIELD(totalExplainOutput[i].executionDuration);
+
+		/* copy the totalReceivedTupleData (uint64) */
+		COPY_SCALAR_FIELD(totalExplainOutput[i].totalReceivedTupleData);
+	}
+
+	COPY_SCALAR_FIELD(numTasksOutput);
+	COPY_SCALAR_FIELD(ntuples);
 }
 
 
@@ -287,6 +312,15 @@ CopyTaskQuery(Task *newnode, Task *from)
 			break;
 		}
 
+		case TASK_QUERY_LOCAL_PLAN:
+		{
+			newnode->taskQuery.data.localCompiled =
+				(LocalCompilation *) palloc0(sizeof(LocalCompilation));
+			COPY_NODE_FIELD(taskQuery.data.localCompiled->plan);
+			COPY_NODE_FIELD(taskQuery.data.localCompiled->query);
+			break;
+		}
+
 		default:
 		{
 			break;

src/backend/distributed/utils/citus_outfuncs.c

@@ -215,6 +215,48 @@ OutDistributedSubPlan(OUTFUNC_ARGS)
 
 	WRITE_UINT_FIELD(subPlanId);
 	WRITE_NODE_FIELD(plan);
+	WRITE_UINT64_FIELD(bytesSentPerWorker);
+	WRITE_INT_FIELD(remoteWorkerCount);
+	WRITE_FLOAT_FIELD(durationMillisecs, "%.2f");
+	WRITE_BOOL_FIELD(writeLocalFile);
+
+	appendStringInfoString(str, " totalExplainOutput [");
+	for (int i = 0; i < node->numTasksOutput; i++)
+	{
+		const SubPlanExplainOutputData *e = &node->totalExplainOutput[i];
+
+		/* skip empty slots */
+		if (e->explainOutput == NULL &&
+			e->executionDuration == 0
+				&& e->totalReceivedTupleData == 0)
+		{
+			continue;
+		}
+
+		if (i > 0)
+		{
+			appendStringInfoChar(str, ' ');
+		}
+
+		appendStringInfoChar(str, '(');
+
+		/* string pointer – prints quoted or NULL */
+		WRITE_STRING_FIELD(totalExplainOutput[i].explainOutput);
+
+		/* double field */
+		WRITE_FLOAT_FIELD(totalExplainOutput[i].executionDuration, "%.2f");
+
+		/* 64-bit unsigned – use the uint64 macro */
+		WRITE_UINT64_FIELD(totalExplainOutput[i].totalReceivedTupleData);
+
+		appendStringInfoChar(str, ')');
+	}
+
+	appendStringInfoChar(str, ']');
+
+	WRITE_INT_FIELD(numTasksOutput);
+	WRITE_FLOAT_FIELD(ntuples, "%.2f");
+
 }
 
 void

src/backend/distributed/utils/colocation_utils.c

@@ -815,13 +815,14 @@ UpdateRelationColocationGroup(Oid distributedRelationId, uint32 colocationId,
 	bool indexOK = true;
 	int scanKeyCount = 1;
 	ScanKeyData scanKey[1];
-	Datum values[Natts_pg_dist_partition];
-	bool isNull[Natts_pg_dist_partition];
-	bool replace[Natts_pg_dist_partition];
 
 	Relation pgDistPartition = table_open(DistPartitionRelationId(), RowExclusiveLock);
 	TupleDesc tupleDescriptor = RelationGetDescr(pgDistPartition);
 
+	Datum *values = (Datum *) palloc0(tupleDescriptor->natts * sizeof(Datum));
+	bool *isNull = (bool *) palloc0(tupleDescriptor->natts * sizeof(bool));
+	bool *replace = (bool *) palloc0(tupleDescriptor->natts * sizeof(bool));
+
 	ScanKeyInit(&scanKey[0], Anum_pg_dist_partition_logicalrelid,
 				BTEqualStrategyNumber, F_OIDEQ, ObjectIdGetDatum(distributedRelationId));
 
@@ -838,10 +839,6 @@ UpdateRelationColocationGroup(Oid distributedRelationId, uint32 colocationId,
 							   distributedRelationName)));
 	}
 
-	memset(values, 0, sizeof(values));
-	memset(isNull, false, sizeof(isNull));
-	memset(replace, false, sizeof(replace));
-
 	values[Anum_pg_dist_partition_colocationid - 1] = UInt32GetDatum(colocationId);
 	isNull[Anum_pg_dist_partition_colocationid - 1] = false;
 	replace[Anum_pg_dist_partition_colocationid - 1] = true;
@@ -858,6 +855,10 @@ UpdateRelationColocationGroup(Oid distributedRelationId, uint32 colocationId,
 	systable_endscan(scanDescriptor);
 	table_close(pgDistPartition, NoLock);
 
+	pfree(values);
+	pfree(isNull);
+	pfree(replace);
+
 	bool shouldSyncMetadata = ShouldSyncTableMetadata(distributedRelationId);
 	if (shouldSyncMetadata && !localOnly)
 	{
@@ -998,10 +999,12 @@ ColocationGroupTableList(uint32 colocationId, uint32 count)
 													indexOK, NULL, scanKeyCount, scanKey);
 
 	HeapTuple heapTuple = systable_getnext(scanDescriptor);
+	Datum *datumArray = (Datum *) palloc(tupleDescriptor->natts * sizeof(Datum));
+	bool *isNullArray = (bool *) palloc(tupleDescriptor->natts * sizeof(bool));
 	while (HeapTupleIsValid(heapTuple))
 	{
-		bool isNullArray[Natts_pg_dist_partition];
+		memset(datumArray, 0, tupleDescriptor->natts * sizeof(Datum));
-		Datum datumArray[Natts_pg_dist_partition];
+		memset(isNullArray, 0, tupleDescriptor->natts * sizeof(bool));
 		heap_deform_tuple(heapTuple, tupleDescriptor, datumArray, isNullArray);
 		Oid colocatedTableId = DatumGetObjectId(
 			datumArray[Anum_pg_dist_partition_logicalrelid - 1]);
@@ -1020,6 +1023,8 @@ ColocationGroupTableList(uint32 colocationId, uint32 count)
 			break;
 		}
 	}
+	pfree(datumArray);
+	pfree(isNullArray);
 
 	systable_endscan(scanDescriptor);
 	table_close(pgDistPartition, AccessShareLock);
@@ -1192,10 +1197,12 @@ ColocatedTableId(int32 colocationId)
 													indexOK, NULL, scanKeyCount, scanKey);
 
 	HeapTuple heapTuple = systable_getnext(scanDescriptor);
+	Datum *datumArray = (Datum *) palloc(tupleDescriptor->natts * sizeof(Datum));
+	bool *isNullArray = (bool *) palloc(tupleDescriptor->natts * sizeof(bool));
 	while (HeapTupleIsValid(heapTuple))
 	{
-		bool isNullArray[Natts_pg_dist_partition];
+		memset(datumArray, 0, tupleDescriptor->natts * sizeof(Datum));
-		Datum datumArray[Natts_pg_dist_partition];
+		memset(isNullArray, 0, tupleDescriptor->natts * sizeof(bool));
 		heap_deform_tuple(heapTuple, tupleDescriptor, datumArray, isNullArray);
 		colocatedTableId = DatumGetObjectId(
 			datumArray[Anum_pg_dist_partition_logicalrelid - 1]);
@@ -1223,6 +1230,8 @@ ColocatedTableId(int32 colocationId)
 
 		heapTuple = systable_getnext(scanDescriptor);
 	}
+	pfree(datumArray);
+	pfree(isNullArray);
 
 	systable_endscan(scanDescriptor);
 	table_close(pgDistPartition, AccessShareLock);

src/include/distributed/citus_ruleutils.h

@@ -44,6 +44,7 @@ extern bool contain_nextval_expression_walker(Node *node, void *context);
 extern char * pg_get_replica_identity_command(Oid tableRelationId);
 extern List * pg_get_row_level_security_commands(Oid relationId);
 extern const char * RoleSpecString(RoleSpec *spec, bool withQuoteIdentifier);
+extern List * ExpandMergedSubscriptingRefEntries(List *targetEntryList);
 extern char * flatten_reloptions(Oid relid);
 
 /* Function declarations for version dependent PostgreSQL ruleutils functions */
@@ -60,5 +61,6 @@ extern char * generate_operator_name(Oid operid, Oid arg1, Oid arg2);
 extern List * getOwnedSequences_internal(Oid relid, AttrNumber attnum, char deptype);
 extern void AppendOptionListToString(StringInfo stringData, List *options);
 
+extern void ensure_update_targetlist_in_param_order(List *targetList);
 
 #endif /* CITUS_RULEUTILS_H */

src/include/distributed/deparse_shard_query.h

@@ -27,7 +27,9 @@ extern bool UpdateRelationToShardNames(Node *node, List *relationShardList);
 extern void SetTaskQueryIfShouldLazyDeparse(Task *task, Query *query);
 extern void SetTaskQueryString(Task *task, char *queryString);
 extern void SetTaskQueryStringList(Task *task, List *queryStringList);
+extern void SetTaskQueryPlan(Task *task, Query *query, PlannedStmt *localPlan);
 extern char * TaskQueryString(Task *task);
+extern PlannedStmt * TaskQueryLocalPlan(Task *task);
 extern char * TaskQueryStringAtIndex(Task *task, int index);
 extern int GetTaskQueryType(Task *task);
 extern void AddInsertAliasIfNeeded(Query *query);

src/include/distributed/distributed_planner.h

@@ -99,6 +99,12 @@ typedef struct FastPathRestrictionContext
 	 * Set to true when distKey = Param; in the queryTree
 	 */
 	bool distributionKeyHasParam;
+
+	/*
+	 * Indicates to hold off calling the fast path planner until its
+	 * known if the shard is local or not.
+	 */
+	bool delayFastPathPlanning;
 } FastPathRestrictionContext;
 
 typedef struct PlannerRestrictionContext

src/include/distributed/metadata_utility.h

@@ -466,4 +466,5 @@ extern bool IsBackgroundJobStatusTerminal(BackgroundJobStatus status);
 extern bool IsBackgroundTaskStatusTerminal(BackgroundTaskStatus status);
 extern Oid BackgroundJobStatusOid(BackgroundJobStatus status);
 extern Oid BackgroundTaskStatusOid(BackgroundTaskStatus status);
+extern int GetAutoConvertedAttrIndexInPgDistPartition(TupleDesc tupleDEsc);
 #endif   /* METADATA_UTILITY_H */

src/include/distributed/multi_executor.h

@@ -146,8 +146,8 @@ extern void ExecuteQueryStringIntoDestReceiver(const char *queryString, ParamLis
 											   DestReceiver *dest);
 extern void ExecuteQueryIntoDestReceiver(Query *query, ParamListInfo params,
 										 DestReceiver *dest);
-extern void ExecutePlanIntoDestReceiver(PlannedStmt *queryPlan, ParamListInfo params,
+extern uint64 ExecutePlanIntoDestReceiver(PlannedStmt *queryPlan, ParamListInfo params,
-										DestReceiver *dest);
+										  DestReceiver *dest);
 extern void SetLocalMultiShardModifyModeToSequential(void);
 extern void EnsureSequentialMode(ObjectType objType);
 extern void SetLocalForceMaxQueryParallelization(void);

src/include/distributed/multi_physical_planner.h

@@ -174,9 +174,16 @@ typedef enum TaskQueryType
 	TASK_QUERY_NULL,
 	TASK_QUERY_TEXT,
 	TASK_QUERY_OBJECT,
-	TASK_QUERY_TEXT_LIST
+	TASK_QUERY_TEXT_LIST,
+	TASK_QUERY_LOCAL_PLAN,
 } TaskQueryType;
 
+typedef struct LocalCompilation
+{
+	PlannedStmt *plan; /* the local plan for this task */
+	Query *query; /* query to deparse for EXPLAIN ANALYZE or local command logging */
+} LocalCompilation;
+
 typedef struct TaskQuery
 {
 	TaskQueryType queryType;
@@ -219,6 +226,15 @@ typedef struct TaskQuery
 		 * when we want to access each query string.
 		 */
 		List *queryStringList;
+
+		/*
+		 * For tasks that can be executed locally, this field contains the
+		 * local plan for the task. This is only set when the shard that the
+		 * task is assigned to is local to the node that executes the task.
+		 * The query field is used to deparse the query for EXPLAIN ANALYZE
+		 * or local command logging.
+		 */
+		LocalCompilation *localCompiled; /* only applies to local tasks */
 	}data;
 }TaskQuery;
 
@@ -474,6 +490,24 @@ typedef struct DistributedPlan
 } DistributedPlan;
 
 
+/*
+ * SubPlanExplainOutputData Holds the EXPLAIN ANALYZE output and collected
+ * statistics for a single task executed by a worker during distributed
+ * query execution.
+ * explainOutput — raw EXPLAIN ANALYZE output for the task
+ * executionDuration — wall‑clock time taken to run the task
+ * totalReceivedTupleData — total bytes of tuple data received from the worker
+ */
+typedef struct SubPlanExplainOutputData
+{
+	char *explainOutput;
+	double executionDuration;
+	double executionNtuples;
+	double executionNloops;
+	uint64 totalReceivedTupleData;
+} SubPlanExplainOutputData;
+
+
 /*
  * DistributedSubPlan contains a subplan of a distributed plan. Subplans are
  * executed before the distributed query and their results are written to
@@ -492,6 +526,9 @@ typedef struct DistributedSubPlan
 	uint32 remoteWorkerCount;
 	double durationMillisecs;
 	bool writeLocalFile;
+	SubPlanExplainOutputData *totalExplainOutput;
+	uint32 numTasksOutput; /* actual size of the above array */
+	double ntuples; /* total tuples produced */
 } DistributedSubPlan;
 
 

src/include/distributed/multi_router_planner.h

@@ -28,6 +28,7 @@
 
 extern bool EnableRouterExecution;
 extern bool EnableFastPathRouterPlanner;
+extern bool EnableLocalFastPathQueryOptimization;
 
 extern bool EnableNonColocatedRouterQueryPushdown;
 
@@ -91,16 +92,19 @@ extern void GenerateSingleShardRouterTaskList(Job *job,
 											  List *relationShardList,
 											  List *placementList,
 											  uint64 shardId,
-											  bool isLocalTableModification);
+											  bool isLocalTableModification,
+											  bool delayedFastPath);
 
 /*
  * FastPathPlanner is a subset of router planner, that's why we prefer to
  * keep the external function here.
  */extern PlannedStmt * GeneratePlaceHolderPlannedStmt(Query *parse);
 
+extern void FastPathPreprocessParseTree(Query *parse);
 extern PlannedStmt * FastPathPlanner(Query *originalQuery, Query *parse, ParamListInfo
 									 boundParams);
-extern bool FastPathRouterQuery(Query *query, Node **distributionKeyValue);
+extern bool FastPathRouterQuery(Query *query,
+								FastPathRestrictionContext *fastPathContext);
 extern bool JoinConditionIsOnFalse(List *relOptInfo);
 extern Oid ResultRelationOidForQuery(Query *query);
 extern DeferredErrorMessage * TargetlistAndFunctionsSupported(Oid resultRelationId,
@@ -120,5 +124,7 @@ extern Job * RouterJob(Query *originalQuery,
 					   DeferredErrorMessage **planningError);
 extern bool ContainsOnlyLocalOrReferenceTables(RTEListProperties *rteProperties);
 extern RangeTblEntry * ExtractSourceResultRangeTableEntry(Query *query);
+extern void CheckAndBuildDelayedFastPathPlan(DistributedPlanningContext *planContext,
+											 DistributedPlan *plan);
 
 #endif /* MULTI_ROUTER_PLANNER_H */

src/include/distributed/subplan_execution.h

@@ -17,7 +17,7 @@
 extern int MaxIntermediateResult;
 extern int SubPlanLevel;
 
-extern void ExecuteSubPlans(DistributedPlan *distributedPlan);
+extern void ExecuteSubPlans(DistributedPlan *distributedPlan, bool explainAnalyzeEnabled);
 
 /**
  * IntermediateResultsHashEntry is used to store which nodes need to receive

src/include/pg_version_compat.h

@@ -13,6 +13,10 @@
 
 #include "pg_version_constants.h"
 
+/* we need these for PG-18’s PushActiveSnapshot/PopActiveSnapshot APIs */
+#include "access/xact.h"
+#include "utils/snapmgr.h"
+
 #if PG_VERSION_NUM >= PG_VERSION_18
 #define create_foreignscan_path_compat(a, b, c, d, e, f, g, h, i, j, k) \
 	create_foreignscan_path( \
@@ -36,6 +40,14 @@
 /* PG-18 unified row-compare operator codes under COMPARE_* */
 #define ROWCOMPARE_NE COMPARE_NE
 
+#define CATALOG_INSERT_WITH_SNAPSHOT(rel, tup) \
+	do { \
+		Snapshot __snap = GetTransactionSnapshot(); \
+		PushActiveSnapshot(__snap); \
+		CatalogTupleInsert((rel), (tup)); \
+		PopActiveSnapshot(); \
+	} while (0)
+
 #elif PG_VERSION_NUM >= PG_VERSION_17
 #define create_foreignscan_path_compat(a, b, c, d, e, f, g, h, i, j, k) \
 	create_foreignscan_path( \
@@ -43,6 +55,10 @@
 		(e), (f), \
 		(g), (h), (i), (j), (k) \
 		)
+
+/* no-op wrapper on older PGs */
+#define CATALOG_INSERT_WITH_SNAPSHOT(rel, tup) \
+	CatalogTupleInsert((rel), (tup))
 #endif
 
 #if PG_VERSION_NUM >= PG_VERSION_17
@@ -453,6 +469,10 @@ getStxstattarget_compat(HeapTuple tup)
 									   k) create_foreignscan_path(a, b, c, d, e, f, g, h, \
 																  i, k)
 
+/* no-op wrapper on older PGs */
+#define CATALOG_INSERT_WITH_SNAPSHOT(rel, tup) \
+	CatalogTupleInsert((rel), (tup))
+
 #define getProcNo_compat(a) (a->pgprocno)
 #define getLxid_compat(a) (a->lxid)
 

src/test/regress/Pipfile.lock

@@ -119,11 +119,12 @@
         },
         "certifi": {
             "hashes": [
-                "sha256:0569859f95fc761b18b45ef421b1290a0f65f147e92a1e5eb3e635f9a5e4e66f",
+                "sha256:5a1e7645bc0ec61a09e26c36f6106dd4cf40c6db3a1fb6352b0244e7fb057c7b",
-                "sha256:dc383c07b76109f368f6106eee2b593b04a011ea4d55f652c6ca24a754d1cdd1"
+                "sha256:c198e21b1289c2ab85ee4e67bb4b4ef3ead0892059901a8d5b622f24a1101e90"
             ],
+            "index": "pypi",
             "markers": "python_version >= '3.6'",
-            "version": "==2024.2.2"
+            "version": "==2024.7.4"
         },
         "cffi": {
             "hashes": [

src/test/regress/citus_tests/run_test.py

@@ -147,6 +147,7 @@ DEPS = {
     "multi_mx_modifying_xacts": TestDeps(None, ["multi_mx_create_table"]),
     "multi_mx_router_planner": TestDeps(None, ["multi_mx_create_table"]),
     "multi_mx_copy_data": TestDeps(None, ["multi_mx_create_table"]),
+    "multi_mx_modifications": TestDeps(None, ["multi_mx_create_table"]),
     "multi_mx_schema_support": TestDeps(None, ["multi_mx_copy_data"]),
     "multi_simple_queries": TestDeps("base_schedule"),
     "create_single_shard_table": TestDeps("minimal_schedule"),
@@ -225,6 +226,15 @@ DEPS = {
         repeatable=False,
     ),
     "pg17": TestDeps("minimal_schedule", ["multi_behavioral_analytics_create_table"]),
+    "multi_subquery_misc": TestDeps(
+        "minimal_schedule", ["multi_behavioral_analytics_create_table"]
+    ),
+    "multi_subquery_union": TestDeps(
+        "minimal_schedule", ["multi_behavioral_analytics_create_table"]
+    ),
+    "multi_subquery_in_where_clause": TestDeps(
+        "minimal_schedule", ["multi_behavioral_analytics_create_table"]
+    ),
 }
 
 

src/test/regress/expected/insert_select_single_shard_table.out

@@ -226,10 +226,12 @@ DEBUG:  Local tables cannot be used in distributed queries.
 DEBUG:  Wrapping relation "citus_local_table" to a subquery
 DEBUG:  Distributed planning for a fast-path router query
 DEBUG:  Creating router plan
+DEBUG:  Fast-path router query: created local execution plan to avoid deparse and compile of shard query
 DEBUG:  generating subplan XXX_1 for subquery SELECT a FROM insert_select_single_shard_table.citus_local_table WHERE true
 DEBUG:  Plan XXX query after replacing subqueries and CTEs: SELECT nullkey_c1_t1.a, nullkey_c1_t1.b FROM (insert_select_single_shard_table.nullkey_c1_t1 JOIN (SELECT citus_local_table_1.a, NULL::integer AS b FROM (SELECT intermediate_result.a FROM read_intermediate_result('XXX_1'::text, 'binary'::citus_copy_format) intermediate_result(a integer)) citus_local_table_1) citus_local_table USING (a))
 DEBUG:  Creating router plan
 DEBUG:  Collecting INSERT ... SELECT results on coordinator
+DEBUG:  Local executor: Using task's cached local plan for task 0
 -- use a postgres local table
 INSERT INTO distributed_table_c1_t1 SELECT nullkey_c1_t2.a, nullkey_c1_t2.b FROM nullkey_c1_t2 JOIN postgres_local_table USING (a);
 DEBUG:  distributed INSERT ... SELECT cannot select from distributed tables and local tables at the same time
@@ -338,10 +340,12 @@ DEBUG:  Local tables cannot be used in distributed queries.
 DEBUG:  Wrapping relation "citus_local_table" to a subquery
 DEBUG:  Distributed planning for a fast-path router query
 DEBUG:  Creating router plan
+DEBUG:  Fast-path router query: created local execution plan to avoid deparse and compile of shard query
 DEBUG:  generating subplan XXX_1 for subquery SELECT a FROM insert_select_single_shard_table.citus_local_table WHERE true
 DEBUG:  Plan XXX query after replacing subqueries and CTEs: SELECT nullkey_c1_t1.a, nullkey_c1_t1.b FROM (insert_select_single_shard_table.nullkey_c1_t1 JOIN (SELECT citus_local_table_1.a, NULL::integer AS b FROM (SELECT intermediate_result.a FROM read_intermediate_result('XXX_1'::text, 'binary'::citus_copy_format) intermediate_result(a integer)) citus_local_table_1) citus_local_table USING (a))
 DEBUG:  Creating router plan
 DEBUG:  Collecting INSERT ... SELECT results on coordinator
+DEBUG:  Local executor: Using task's cached local plan for task 0
 -- use a postgres local table
 INSERT INTO reference_table SELECT nullkey_c1_t2.a, nullkey_c1_t2.b FROM nullkey_c1_t2 JOIN postgres_local_table USING (a);
 DEBUG:  distributed INSERT ... SELECT cannot select from distributed tables and local tables at the same time
@@ -400,10 +404,12 @@ DEBUG:  Local tables cannot be used in distributed queries.
 DEBUG:  Wrapping relation "citus_local_table" to a subquery
 DEBUG:  Distributed planning for a fast-path router query
 DEBUG:  Creating router plan
+DEBUG:  Fast-path router query: created local execution plan to avoid deparse and compile of shard query
 DEBUG:  generating subplan XXX_1 for subquery SELECT a FROM insert_select_single_shard_table.citus_local_table WHERE true
 DEBUG:  Plan XXX query after replacing subqueries and CTEs: SELECT nullkey_c1_t1.a, nullkey_c1_t1.b FROM (insert_select_single_shard_table.nullkey_c1_t1 JOIN (SELECT citus_local_table_1.a, NULL::integer AS b FROM (SELECT intermediate_result.a FROM read_intermediate_result('XXX_1'::text, 'binary'::citus_copy_format) intermediate_result(a integer)) citus_local_table_1) citus_local_table USING (a))
 DEBUG:  Creating router plan
 DEBUG:  Collecting INSERT ... SELECT results on coordinator
+DEBUG:  Local executor: Using task's cached local plan for task 0
 -- use a postgres local table
 INSERT INTO citus_local_table SELECT nullkey_c1_t2.a, nullkey_c1_t2.b FROM nullkey_c1_t2 JOIN postgres_local_table USING (a);
 DEBUG:  distributed INSERT ... SELECT cannot select from distributed tables and local tables at the same time
@@ -416,6 +422,8 @@ DEBUG:  Collecting INSERT ... SELECT results on coordinator
 SELECT avg(a), avg(b) FROM citus_local_table ORDER BY 1, 2;
 DEBUG:  Distributed planning for a fast-path router query
 DEBUG:  Creating router plan
+DEBUG:  Fast-path router query: created local execution plan to avoid deparse and compile of shard query
+DEBUG:  Local executor: Using task's cached local plan for task 0
         avg         |        avg
 ---------------------------------------------------------------------
  4.5270270270270270 | 4.5270270270270270
@@ -458,7 +466,9 @@ DEBUG:  Creating router plan
 DEBUG:  distributed INSERT ... SELECT cannot select from a local relation when inserting into a distributed table
 DEBUG:  Distributed planning for a fast-path router query
 DEBUG:  Creating router plan
+DEBUG:  Fast-path router query: created local execution plan to avoid deparse and compile of shard query
 DEBUG:  Collecting INSERT ... SELECT results on coordinator
+DEBUG:  Local executor: Using task's cached local plan for task 0
 INSERT INTO nullkey_c1_t1 SELECT citus_local_table.a, citus_local_table.b FROM citus_local_table JOIN reference_table USING (a) JOIN postgres_local_table USING (a) ORDER BY 1,2 OFFSET 7;
 DEBUG:  Creating router plan
 DEBUG:  distributed INSERT ... SELECT cannot select from a local table
@@ -470,10 +480,12 @@ DEBUG:  Local tables cannot be used in distributed queries.
 DEBUG:  Wrapping relation "citus_local_table" to a subquery
 DEBUG:  Distributed planning for a fast-path router query
 DEBUG:  Creating router plan
+DEBUG:  Fast-path router query: created local execution plan to avoid deparse and compile of shard query
 DEBUG:  generating subplan XXX_1 for subquery SELECT a, b FROM insert_select_single_shard_table.citus_local_table WHERE true
 DEBUG:  Plan XXX query after replacing subqueries and CTEs: SELECT citus_local_table.a, citus_local_table.b FROM ((SELECT citus_local_table_1.a, citus_local_table_1.b FROM (SELECT intermediate_result.a, intermediate_result.b FROM read_intermediate_result('XXX_1'::text, 'binary'::citus_copy_format) intermediate_result(a integer, b integer)) citus_local_table_1) citus_local_table JOIN insert_select_single_shard_table.nullkey_c1_t1 USING (a))
 DEBUG:  Creating router plan
 DEBUG:  Collecting INSERT ... SELECT results on coordinator
+DEBUG:  Local executor: Using task's cached local plan for task 0
 -- use a distributed table
 INSERT INTO nullkey_c1_t1 SELECT distributed_table_c1_t2.a, distributed_table_c1_t2.b FROM distributed_table_c1_t2;
 DEBUG:  INSERT target relation and all source relations of the SELECT must be colocated in distributed INSERT ... SELECT

src/test/regress/expected/local_execution_local_plan.out

@@ -0,0 +1,377 @@
+-- Test local execution with local plan in a sharded environment.
+-- This is an enhancement to local execution where instead of deparsing
+-- and compiling the shard query, the planner replaces the OID of the
+-- distributed table with the OID of the local shard in the parse tree
+-- and plans that.
+--
+-- https://github.com/citusdata/citus/pull/8035
+CREATE SCHEMA local_shard_execution_local_plan;
+SET search_path TO local_shard_execution_local_plan;
+SET citus.next_shard_id TO 86000000;
+-- Test row-based sharding
+SET citus.shard_replication_factor TO 1;
+CREATE TABLE test_tbl (a int, b int, data_f double precision);
+SELECT create_distributed_table('test_tbl', 'a');
+ create_distributed_table
+---------------------------------------------------------------------
+
+(1 row)
+
+SELECT setseed(0.42); -- make the random data inserted deterministic
+ setseed
+---------------------------------------------------------------------
+
+(1 row)
+
+INSERT INTO test_tbl
+SELECT (random()*20)::int AS a,
+       (random()*20)::int AS b,
+       random()*10000.0 AS data_f
+FROM generate_series(1, 10000);
+-- Put the shard on worker 1 to ensure consistent test output across different schedules
+SET client_min_messages to ERROR; -- suppress warning if shard is already on worker 1
+SELECT citus_move_shard_placement(86000000, 'localhost', :worker_2_port, 'localhost', :worker_1_port, 'block_writes');
+ citus_move_shard_placement
+---------------------------------------------------------------------
+
+(1 row)
+
+SELECT public.wait_for_resource_cleanup(); -- otherwise fails flakiness tests
+ wait_for_resource_cleanup
+---------------------------------------------------------------------
+
+(1 row)
+
+RESET client_min_messages;
+\c - - - :worker_1_port
+SET search_path TO local_shard_execution_local_plan;
+SET client_min_messages TO DEBUG2;
+SET citus.log_remote_commands TO ON;
+SET citus.log_local_commands TO ON;
+-- This query resolves to a single shard (aka fast path)
+-- which is located on worker_1; with client_min_messages
+-- at DEBUG2 we see a message that the planner is avoiding
+-- query deparse and plan
+SELECT b, AVG(data_f), MIN(data_f), MAX(data_f), COUNT(1)
+FROM test_tbl
+WHERE a = 8 AND b IN (1,3,5,8,13,21)
+GROUP BY b
+ORDER BY b;
+DEBUG:  Distributed planning for a fast-path router query
+DEBUG:  Creating router plan
+DEBUG:  Fast-path router query: created local execution plan to avoid deparse and compile of shard query
+DEBUG:  query has a single distribution column value: 8
+NOTICE:  executing the command locally: SELECT b, avg(data_f) AS avg, min(data_f) AS min, max(data_f) AS max, count(1) AS count FROM local_shard_execution_local_plan.test_tbl_86000000 test_tbl WHERE ((a OPERATOR(pg_catalog.=) 8) AND (b OPERATOR(pg_catalog.=) ANY (ARRAY[1, 3, 5, 8, 13, 21]))) GROUP BY b ORDER BY b
+DEBUG:  Local executor: Using task's cached local plan for task 0
+ b  |       avg        |       min        |       max        | count
+---------------------------------------------------------------------
+  1 | 4930.97455169836 |  130.09338419238 | 9961.37766951669 |    21
+  3 | 5587.38637430731 | 1230.07668620184 | 9937.96225230491 |    23
+  5 | 3987.47953221387 | 437.362539823312 | 9729.29912509372 |    25
+  8 | 5028.45408903437 | 593.546207093687 | 9869.93823005882 |    27
+ 13 |  3900.7835426648 | 510.078935445757 | 7784.07104505068 |    18
+(5 rows)
+
+BEGIN;
+  -- force accessing local placements via remote connections first
+  SET citus.enable_local_execution TO false;
+  RESET client_min_messages;
+  RESET citus.log_remote_commands;
+  RESET citus.log_local_commands;
+  SELECT count(*), b FROM test_tbl GROUP BY b ORDER BY b;
+ count | b
+---------------------------------------------------------------------
+   246 |  0
+   530 |  1
+   517 |  2
+   530 |  3
+   513 |  4
+   487 |  5
+   501 |  6
+   490 |  7
+   501 |  8
+   480 |  9
+   510 | 10
+   472 | 11
+   484 | 12
+   505 | 13
+   463 | 14
+   484 | 15
+   516 | 16
+   523 | 17
+   507 | 18
+   481 | 19
+   260 | 20
+(21 rows)
+
+  -- Now, even if we enable local execution back before the query that
+  -- could normally benefit from fast path local query optimizations,
+  -- this time it won't be the case because local execution was implicitly
+  -- disabled by Citus as we accessed local shard placements via remote
+  -- connections.
+  SET citus.enable_local_execution TO true;
+  SET client_min_messages TO DEBUG2;
+  SET citus.log_remote_commands TO ON;
+  SET citus.log_local_commands TO ON;
+  SELECT b, AVG(data_f), MIN(data_f), MAX(data_f), COUNT(1)
+  FROM test_tbl
+  WHERE a = 8 AND b IN (1,3,5,8,13,21)
+  GROUP BY b
+  ORDER BY b;
+DEBUG:  Distributed planning for a fast-path router query
+DEBUG:  Creating router plan
+DEBUG:  query has a single distribution column value: 8
+NOTICE:  issuing SELECT b, avg(data_f) AS avg, min(data_f) AS min, max(data_f) AS max, count(1) AS count FROM local_shard_execution_local_plan.test_tbl_86000000 test_tbl WHERE ((a OPERATOR(pg_catalog.=) 8) AND (b OPERATOR(pg_catalog.=) ANY (ARRAY[1, 3, 5, 8, 13, 21]))) GROUP BY b ORDER BY b
+DETAIL:  on server postgres@localhost:xxxxx connectionId: xxxxxxx
+ b  |       avg        |       min        |       max        | count
+---------------------------------------------------------------------
+  1 | 4930.97455169836 |  130.09338419238 | 9961.37766951669 |    21
+  3 | 5587.38637430731 | 1230.07668620184 | 9937.96225230491 |    23
+  5 | 3987.47953221387 | 437.362539823312 | 9729.29912509372 |    25
+  8 | 5028.45408903437 | 593.546207093687 | 9869.93823005882 |    27
+ 13 |  3900.7835426648 | 510.078935445757 | 7784.07104505068 |    18
+(5 rows)
+
+SET client_min_messages TO ERROR; -- keep COMMIT output quiet
+COMMIT;
+SET client_min_messages TO DEBUG2;
+SET citus.enable_local_fast_path_query_optimization TO OFF;
+-- With local execution local plan disabled, the same query
+-- does query deparse and planning of the shard query and
+-- provides the same results
+SELECT b, AVG(data_f), MIN(data_f), MAX(data_f), COUNT(1)
+FROM test_tbl
+WHERE a = 8 AND b IN (1,3,5,8,13,21)
+GROUP BY b
+ORDER BY b;
+DEBUG:  Distributed planning for a fast-path router query
+DEBUG:  Creating router plan
+DEBUG:  query has a single distribution column value: 8
+NOTICE:  executing the command locally: SELECT b, avg(data_f) AS avg, min(data_f) AS min, max(data_f) AS max, count(1) AS count FROM local_shard_execution_local_plan.test_tbl_86000000 test_tbl WHERE ((a OPERATOR(pg_catalog.=) 8) AND (b OPERATOR(pg_catalog.=) ANY (ARRAY[1, 3, 5, 8, 13, 21]))) GROUP BY b ORDER BY b
+ b  |       avg        |       min        |       max        | count
+---------------------------------------------------------------------
+  1 | 4930.97455169836 |  130.09338419238 | 9961.37766951669 |    21
+  3 | 5587.38637430731 | 1230.07668620184 | 9937.96225230491 |    23
+  5 | 3987.47953221387 | 437.362539823312 | 9729.29912509372 |    25
+  8 | 5028.45408903437 | 593.546207093687 | 9869.93823005882 |    27
+ 13 |  3900.7835426648 | 510.078935445757 | 7784.07104505068 |    18
+(5 rows)
+
+\c - - - :worker_2_port
+SET search_path TO local_shard_execution_local_plan;
+SET client_min_messages TO DEBUG2;
+SET citus.log_remote_commands TO ON;
+SET citus.log_local_commands TO ON;
+-- Run the same query on the other worker - the local
+-- execution path is not taken because the shard is not
+-- local to this worker
+SELECT b, AVG(data_f), MIN(data_f), MAX(data_f), COUNT(1)
+FROM test_tbl
+WHERE a = 8 AND b IN (1,3,5,8,13,21)
+GROUP BY b
+ORDER BY b;
+DEBUG:  Distributed planning for a fast-path router query
+DEBUG:  Creating router plan
+DEBUG:  query has a single distribution column value: 8
+NOTICE:  issuing SELECT b, avg(data_f) AS avg, min(data_f) AS min, max(data_f) AS max, count(1) AS count FROM local_shard_execution_local_plan.test_tbl_86000000 test_tbl WHERE ((a OPERATOR(pg_catalog.=) 8) AND (b OPERATOR(pg_catalog.=) ANY (ARRAY[1, 3, 5, 8, 13, 21]))) GROUP BY b ORDER BY b
+DETAIL:  on server postgres@localhost:xxxxx connectionId: xxxxxxx
+ b  |       avg        |       min        |       max        | count
+---------------------------------------------------------------------
+  1 | 4930.97455169836 |  130.09338419238 | 9961.37766951669 |    21
+  3 | 5587.38637430731 | 1230.07668620184 | 9937.96225230491 |    23
+  5 | 3987.47953221387 | 437.362539823312 | 9729.29912509372 |    25
+  8 | 5028.45408903437 | 593.546207093687 | 9869.93823005882 |    27
+ 13 |  3900.7835426648 | 510.078935445757 | 7784.07104505068 |    18
+(5 rows)
+
+\c - - - :master_port
+SET search_path TO local_shard_execution_local_plan;
+SET citus.next_shard_id TO 86001000;
+-- Test citus local and reference tables
+CREATE TABLE ref_tbl (a int, b int, data_f double precision);
+SELECT create_reference_table('ref_tbl');
+ create_reference_table
+---------------------------------------------------------------------
+
+(1 row)
+
+SELECT setseed(0.42); -- make the random data inserted deterministic
+ setseed
+---------------------------------------------------------------------
+
+(1 row)
+
+INSERT INTO ref_tbl
+SELECT (random()*20)::int AS a,
+       (random()*20)::int AS b,
+       random()*10000.0 AS data_f
+FROM generate_series(1, 10000);
+SET citus.next_shard_id TO 86002000;
+CREATE TABLE citus_tbl (a int, b int, data_f double precision);
+SELECT citus_set_coordinator_host('localhost', :master_port);
+ citus_set_coordinator_host
+---------------------------------------------------------------------
+
+(1 row)
+
+SELECT citus_add_local_table_to_metadata('citus_tbl');
+ citus_add_local_table_to_metadata
+---------------------------------------------------------------------
+
+(1 row)
+
+INSERT INTO citus_tbl SELECT a, b, data_f FROM ref_tbl;
+SET client_min_messages TO DEBUG2;
+SET citus.log_remote_commands TO ON;
+SET citus.log_local_commands TO ON;
+-- citus local table: can use the fast path optimization
+SELECT b, AVG(data_f), MIN(data_f), MAX(data_f), COUNT(1)
+FROM citus_tbl
+WHERE a = 8 AND b IN (1,3,5,8,13,21)
+GROUP BY b
+ORDER BY b;
+DEBUG:  Distributed planning for a fast-path router query
+DEBUG:  Creating router plan
+DEBUG:  Fast-path router query: created local execution plan to avoid deparse and compile of shard query
+NOTICE:  executing the command locally: SELECT b, avg(data_f) AS avg, min(data_f) AS min, max(data_f) AS max, count(1) AS count FROM local_shard_execution_local_plan.citus_tbl_86002000 citus_tbl WHERE ((a OPERATOR(pg_catalog.=) 8) AND (b OPERATOR(pg_catalog.=) ANY (ARRAY[1, 3, 5, 8, 13, 21]))) GROUP BY b ORDER BY b
+DEBUG:  Local executor: Using task's cached local plan for task 0
+ b  |       avg        |       min        |       max        | count
+---------------------------------------------------------------------
+  1 | 4930.97455169836 |  130.09338419238 | 9961.37766951669 |    21
+  3 | 5587.38637430731 | 1230.07668620184 | 9937.96225230491 |    23
+  5 | 3987.47953221387 | 437.362539823312 | 9729.29912509372 |    25
+  8 | 5028.45408903437 | 593.546207093687 | 9869.93823005882 |    27
+ 13 |  3900.7835426648 | 510.078935445757 | 7784.07104505068 |    18
+(5 rows)
+
+-- reference table: does not use the fast path optimization.
+-- It may be enabled in a future enhancement.
+SELECT b, AVG(data_f), MIN(data_f), MAX(data_f), COUNT(1)
+FROM ref_tbl
+WHERE a = 8 AND b IN (1,3,5,8,13,21)
+GROUP BY b
+ORDER BY b;
+DEBUG:  Distributed planning for a fast-path router query
+DEBUG:  Creating router plan
+NOTICE:  executing the command locally: SELECT b, avg(data_f) AS avg, min(data_f) AS min, max(data_f) AS max, count(1) AS count FROM local_shard_execution_local_plan.ref_tbl_86001000 ref_tbl WHERE ((a OPERATOR(pg_catalog.=) 8) AND (b OPERATOR(pg_catalog.=) ANY (ARRAY[1, 3, 5, 8, 13, 21]))) GROUP BY b ORDER BY b
+ b  |       avg        |       min        |       max        | count
+---------------------------------------------------------------------
+  1 | 4930.97455169836 |  130.09338419238 | 9961.37766951669 |    21
+  3 | 5587.38637430731 | 1230.07668620184 | 9937.96225230491 |    23
+  5 | 3987.47953221387 | 437.362539823312 | 9729.29912509372 |    25
+  8 | 5028.45408903437 | 593.546207093687 | 9869.93823005882 |    27
+ 13 |  3900.7835426648 | 510.078935445757 | 7784.07104505068 |    18
+(5 rows)
+
+\c - - - :master_port
+-- Now test local execution with local plan for a schema sharded table.
+SET citus.enable_schema_based_sharding to on;
+CREATE SCHEMA schema_sharding_test;
+SET search_path TO schema_sharding_test;
+SET citus.next_shard_id TO 87000000;
+SET citus.shard_replication_factor TO 1;
+CREATE TABLE test_tbl (a int, b int, data_f double precision);
+SELECT setseed(0.42); -- make the random data inserted deterministic
+ setseed
+---------------------------------------------------------------------
+
+(1 row)
+
+INSERT INTO test_tbl
+SELECT (random()*20)::int AS a,
+       (random()*20)::int AS b,
+       random()*10000.0 AS data_f
+FROM generate_series(1, 10000);
+-- Put the shard on worker 2 to ensure consistent test output across different schedules
+SET client_min_messages to ERROR; -- suppress warning if shard is already on worker 2
+SELECT citus_move_shard_placement(87000000, 'localhost', :worker_1_port, 'localhost', :worker_2_port, 'block_writes');
+ citus_move_shard_placement
+---------------------------------------------------------------------
+
+(1 row)
+
+SELECT public.wait_for_resource_cleanup(); -- otherwise fails flakiness tests
+ wait_for_resource_cleanup
+---------------------------------------------------------------------
+
+(1 row)
+
+RESET client_min_messages;
+\c - - - :worker_1_port
+SET client_min_messages TO DEBUG2;
+SET citus.log_remote_commands TO ON;
+SET citus.log_local_commands TO ON;
+-- Run the test query on worker_1; with schema based sharding
+-- the data is not local to this worker so local execution
+-- path is not taken.
+SELECT b, AVG(data_f), MIN(data_f), MAX(data_f), COUNT(1)
+FROM schema_sharding_test.test_tbl
+WHERE a = 8 AND b IN (1,3,5,8,13,21)
+GROUP BY b
+ORDER BY b;
+DEBUG:  Distributed planning for a fast-path router query
+DEBUG:  Creating router plan
+NOTICE:  issuing SELECT b, avg(data_f) AS avg, min(data_f) AS min, max(data_f) AS max, count(1) AS count FROM schema_sharding_test.test_tbl_87000000 test_tbl WHERE ((a OPERATOR(pg_catalog.=) 8) AND (b OPERATOR(pg_catalog.=) ANY (ARRAY[1, 3, 5, 8, 13, 21]))) GROUP BY b ORDER BY b
+DETAIL:  on server postgres@localhost:xxxxx connectionId: xxxxxxx
+ b  |       avg        |       min        |       max        | count
+---------------------------------------------------------------------
+  1 | 4930.97455169836 |  130.09338419238 | 9961.37766951669 |    21
+  3 | 5587.38637430731 | 1230.07668620184 | 9937.96225230491 |    23
+  5 | 3987.47953221387 | 437.362539823312 | 9729.29912509372 |    25
+  8 | 5028.45408903437 | 593.546207093687 | 9869.93823005882 |    27
+ 13 |  3900.7835426648 | 510.078935445757 | 7784.07104505068 |    18
+(5 rows)
+
+\c - - - :worker_2_port
+SET client_min_messages TO DEBUG2;
+SET citus.log_remote_commands TO ON;
+SET citus.log_local_commands TO ON;
+-- Run the test query on worker_2; with schema based sharding
+-- the data is local to this worker so local execution
+-- path is taken, and the planner avoids query deparse and
+-- planning of the shard query.
+SELECT b, AVG(data_f), MIN(data_f), MAX(data_f), COUNT(1)
+FROM schema_sharding_test.test_tbl
+WHERE a = 8 AND b IN (1,3,5,8,13,21)
+GROUP BY b
+ORDER BY b;
+DEBUG:  Distributed planning for a fast-path router query
+DEBUG:  Creating router plan
+DEBUG:  Fast-path router query: created local execution plan to avoid deparse and compile of shard query
+NOTICE:  executing the command locally: SELECT b, avg(data_f) AS avg, min(data_f) AS min, max(data_f) AS max, count(1) AS count FROM schema_sharding_test.test_tbl_87000000 test_tbl WHERE ((a OPERATOR(pg_catalog.=) 8) AND (b OPERATOR(pg_catalog.=) ANY (ARRAY[1, 3, 5, 8, 13, 21]))) GROUP BY b ORDER BY b
+DEBUG:  Local executor: Using task's cached local plan for task 0
+ b  |       avg        |       min        |       max        | count
+---------------------------------------------------------------------
+  1 | 4930.97455169836 |  130.09338419238 | 9961.37766951669 |    21
+  3 | 5587.38637430731 | 1230.07668620184 | 9937.96225230491 |    23
+  5 | 3987.47953221387 | 437.362539823312 | 9729.29912509372 |    25
+  8 | 5028.45408903437 | 593.546207093687 | 9869.93823005882 |    27
+ 13 |  3900.7835426648 | 510.078935445757 | 7784.07104505068 |    18
+(5 rows)
+
+SET citus.enable_local_fast_path_query_optimization TO OFF;
+-- Run the test query on worker_2 but with local execution
+-- local plan disabled; now the planner does query deparse
+-- and planning of the shard query.
+SELECT b, AVG(data_f), MIN(data_f), MAX(data_f), COUNT(1)
+FROM schema_sharding_test.test_tbl
+WHERE a = 8 AND b IN (1,3,5,8,13,21)
+GROUP BY b
+ORDER BY b;
+DEBUG:  Distributed planning for a fast-path router query
+DEBUG:  Creating router plan
+NOTICE:  executing the command locally: SELECT b, avg(data_f) AS avg, min(data_f) AS min, max(data_f) AS max, count(1) AS count FROM schema_sharding_test.test_tbl_87000000 test_tbl WHERE ((a OPERATOR(pg_catalog.=) 8) AND (b OPERATOR(pg_catalog.=) ANY (ARRAY[1, 3, 5, 8, 13, 21]))) GROUP BY b ORDER BY b
+ b  |       avg        |       min        |       max        | count
+---------------------------------------------------------------------
+  1 | 4930.97455169836 |  130.09338419238 | 9961.37766951669 |    21
+  3 | 5587.38637430731 | 1230.07668620184 | 9937.96225230491 |    23
+  5 | 3987.47953221387 | 437.362539823312 | 9729.29912509372 |    25
+  8 | 5028.45408903437 | 593.546207093687 | 9869.93823005882 |    27
+ 13 |  3900.7835426648 | 510.078935445757 | 7784.07104505068 |    18
+(5 rows)
+
+\c - - - :master_port
+SET client_min_messages to ERROR;
+DROP SCHEMA local_shard_execution_local_plan CASCADE;
+DROP SCHEMA schema_sharding_test CASCADE;
+RESET ALL;

src/test/regress/expected/local_shard_execution.out

@@ -2410,8 +2410,10 @@ NOTICE:  executing the command locally: UPDATE local_shard_execution.event_respo
 SELECT count(*) FROM event_responses WHERE event_id = 16;
 DEBUG:  Distributed planning for a fast-path router query
 DEBUG:  Creating router plan
+DEBUG:  Fast-path router query: created local execution plan to avoid deparse and compile of shard query
 DEBUG:  query has a single distribution column value: 16
 NOTICE:  executing the command locally: SELECT count(*) AS count FROM local_shard_execution.event_responses_1480001 event_responses WHERE (event_id OPERATOR(pg_catalog.=) 16)
+DEBUG:  Local executor: Using task's cached local plan for task 0
  count
 ---------------------------------------------------------------------
      1
@@ -2420,8 +2422,10 @@ NOTICE:  executing the command locally: SELECT count(*) AS count FROM local_shar
 SELECT count(*) FROM event_responses WHERE event_id = 16;
 DEBUG:  Distributed planning for a fast-path router query
 DEBUG:  Creating router plan
+DEBUG:  Fast-path router query: created local execution plan to avoid deparse and compile of shard query
 DEBUG:  query has a single distribution column value: 16
 NOTICE:  executing the command locally: SELECT count(*) AS count FROM local_shard_execution.event_responses_1480001 event_responses WHERE (event_id OPERATOR(pg_catalog.=) 16)
+DEBUG:  Local executor: Using task's cached local plan for task 0
  count
 ---------------------------------------------------------------------
      1
@@ -2430,8 +2434,10 @@ NOTICE:  executing the command locally: SELECT count(*) AS count FROM local_shar
 UPDATE event_responses SET response = 'no' WHERE event_id = 16;
 DEBUG:  Distributed planning for a fast-path router query
 DEBUG:  Creating router plan
+DEBUG:  Fast-path router query: created local execution plan to avoid deparse and compile of shard query
 DEBUG:  query has a single distribution column value: 16
 NOTICE:  executing the command locally: UPDATE local_shard_execution.event_responses_1480001 event_responses SET response = 'no'::local_shard_execution.invite_resp WHERE (event_id OPERATOR(pg_catalog.=) 16)
+DEBUG:  Local executor: Using task's cached local plan for task 0
 INSERT INTO event_responses VALUES (16, 666, 'maybe')
 ON CONFLICT (event_id, user_id)
 DO UPDATE SET response = EXCLUDED.response RETURNING *;
@@ -2529,8 +2535,10 @@ SET citus.log_remote_commands TO ON;
 SELECT * FROM event_responses_no_pkey WHERE event_id = 2;
 DEBUG:  Distributed planning for a fast-path router query
 DEBUG:  Creating router plan
+DEBUG:  Fast-path router query: created local execution plan to avoid deparse and compile of shard query
 DEBUG:  query has a single distribution column value: 2
 NOTICE:  executing the command locally: SELECT event_id, user_id, response FROM local_shard_execution.event_responses_no_pkey_1480007 event_responses_no_pkey WHERE (event_id OPERATOR(pg_catalog.=) 2)
+DEBUG:  Local executor: Using task's cached local plan for task 0
  event_id | user_id | response
 ---------------------------------------------------------------------
 (0 rows)

src/test/regress/expected/local_shard_execution_dropped_column.out

@@ -193,8 +193,102 @@ execute p4(8);
 NOTICE:  executing the command locally: UPDATE local_shard_execution_dropped_column.t1_2460000 t1 SET a = (a OPERATOR(pg_catalog.+) 1) WHERE (c OPERATOR(pg_catalog.=) 8)
 execute p4(8);
 NOTICE:  executing the command locally: UPDATE local_shard_execution_dropped_column.t1_2460000 t1 SET a = (a OPERATOR(pg_catalog.+) 1) WHERE (c OPERATOR(pg_catalog.=) 8)
+-- Test that "Avoid deparse and planning of shard query for local execution" (*)
+-- does not take the fast path of modifying the parse tree with the shard OID, as
+-- the dropped column means the attribute check between the distributed table and
+-- shard fails. With client_min_messages at DEBUG2, we see "cannot modify parse tree
+-- for local execution", indicating that router planning has detected the difference.
+--
+-- (*) https://github.com/citusdata/citus/pull/8035
+SET client_min_messages to DEBUG2;
+prepare p5(int) as SELECT count(*) FROM t1 WHERE c = 8 and a = $1 GROUP BY c;
+execute p5(5);
+DEBUG:  Distributed planning for a fast-path router query
+DEBUG:  Creating router plan
+DEBUG:  Router planner fast path cannot modify parse tree for local execution: shard table "local_shard_execution_dropped_column.t1_2460000" does not match the distributed table "local_shard_execution_dropped_column.t1"
+DEBUG:  query has a single distribution column value: 8
+NOTICE:  executing the command locally: SELECT count(*) AS count FROM local_shard_execution_dropped_column.t1_2460000 t1 WHERE ((c OPERATOR(pg_catalog.=) 8) AND (a OPERATOR(pg_catalog.=) $1)) GROUP BY c
+ count
+---------------------------------------------------------------------
+(0 rows)
+
+execute p5(5);
+DEBUG:  Distributed planning for a fast-path router query
+DEBUG:  Creating router plan
+DEBUG:  Router planner fast path cannot modify parse tree for local execution: shard table "local_shard_execution_dropped_column.t1_2460000" does not match the distributed table "local_shard_execution_dropped_column.t1"
+DEBUG:  query has a single distribution column value: 8
+NOTICE:  executing the command locally: SELECT count(*) AS count FROM local_shard_execution_dropped_column.t1_2460000 t1 WHERE ((c OPERATOR(pg_catalog.=) 8) AND (a OPERATOR(pg_catalog.=) $1)) GROUP BY c
+ count
+---------------------------------------------------------------------
+(0 rows)
+
+execute p5(5);
+DEBUG:  Distributed planning for a fast-path router query
+DEBUG:  Creating router plan
+DEBUG:  Router planner fast path cannot modify parse tree for local execution: shard table "local_shard_execution_dropped_column.t1_2460000" does not match the distributed table "local_shard_execution_dropped_column.t1"
+DEBUG:  query has a single distribution column value: 8
+NOTICE:  executing the command locally: SELECT count(*) AS count FROM local_shard_execution_dropped_column.t1_2460000 t1 WHERE ((c OPERATOR(pg_catalog.=) 8) AND (a OPERATOR(pg_catalog.=) $1)) GROUP BY c
+ count
+---------------------------------------------------------------------
+(0 rows)
+
+execute p5(5);
+DEBUG:  Distributed planning for a fast-path router query
+DEBUG:  Creating router plan
+DEBUG:  Router planner fast path cannot modify parse tree for local execution: shard table "local_shard_execution_dropped_column.t1_2460000" does not match the distributed table "local_shard_execution_dropped_column.t1"
+DEBUG:  query has a single distribution column value: 8
+NOTICE:  executing the command locally: SELECT count(*) AS count FROM local_shard_execution_dropped_column.t1_2460000 t1 WHERE ((c OPERATOR(pg_catalog.=) 8) AND (a OPERATOR(pg_catalog.=) $1)) GROUP BY c
+ count
+---------------------------------------------------------------------
+(0 rows)
+
+execute p5(5);
+DEBUG:  Distributed planning for a fast-path router query
+DEBUG:  Creating router plan
+DEBUG:  Router planner fast path cannot modify parse tree for local execution: shard table "local_shard_execution_dropped_column.t1_2460000" does not match the distributed table "local_shard_execution_dropped_column.t1"
+DEBUG:  query has a single distribution column value: 8
+NOTICE:  executing the command locally: SELECT count(*) AS count FROM local_shard_execution_dropped_column.t1_2460000 t1 WHERE ((c OPERATOR(pg_catalog.=) 8) AND (a OPERATOR(pg_catalog.=) $1)) GROUP BY c
+ count
+---------------------------------------------------------------------
+(0 rows)
+
+execute p5(5);
+DEBUG:  Distributed planning for a fast-path router query
+DEBUG:  Creating router plan
+DEBUG:  Router planner fast path cannot modify parse tree for local execution: shard table "local_shard_execution_dropped_column.t1_2460000" does not match the distributed table "local_shard_execution_dropped_column.t1"
+DEBUG:  query has a single distribution column value: 8
+NOTICE:  executing the command locally: SELECT count(*) AS count FROM local_shard_execution_dropped_column.t1_2460000 t1 WHERE ((c OPERATOR(pg_catalog.=) 8) AND (a OPERATOR(pg_catalog.=) $1)) GROUP BY c
+ count
+---------------------------------------------------------------------
+(0 rows)
+
+execute p5(5);
+NOTICE:  executing the command locally: SELECT count(*) AS count FROM local_shard_execution_dropped_column.t1_2460000 t1 WHERE ((c OPERATOR(pg_catalog.=) 8) AND (a OPERATOR(pg_catalog.=) $1)) GROUP BY c
+ count
+---------------------------------------------------------------------
+(0 rows)
+
+execute p5(5);
+NOTICE:  executing the command locally: SELECT count(*) AS count FROM local_shard_execution_dropped_column.t1_2460000 t1 WHERE ((c OPERATOR(pg_catalog.=) 8) AND (a OPERATOR(pg_catalog.=) $1)) GROUP BY c
+ count
+---------------------------------------------------------------------
+(0 rows)
+
+execute p5(5);
+NOTICE:  executing the command locally: SELECT count(*) AS count FROM local_shard_execution_dropped_column.t1_2460000 t1 WHERE ((c OPERATOR(pg_catalog.=) 8) AND (a OPERATOR(pg_catalog.=) $1)) GROUP BY c
+ count
+---------------------------------------------------------------------
+(0 rows)
+
+execute p5(5);
+NOTICE:  executing the command locally: SELECT count(*) AS count FROM local_shard_execution_dropped_column.t1_2460000 t1 WHERE ((c OPERATOR(pg_catalog.=) 8) AND (a OPERATOR(pg_catalog.=) $1)) GROUP BY c
+ count
+---------------------------------------------------------------------
+(0 rows)
+
+RESET client_min_messages;
 \c - - - :master_port
--- one another combination is that the shell table
+-- one other combination is that the shell table
 -- has a dropped column but not the shard, via rebalance operation
 SET search_path TO local_shard_execution_dropped_column;
 ALTER TABLE t1 DROP COLUMN a;
@@ -204,6 +298,12 @@ SELECT citus_move_shard_placement(2460000, 'localhost', :worker_1_port, 'localho
 
 (1 row)
 
+SELECT public.wait_for_resource_cleanup(); -- otherwise fails flakiness tests
+ wait_for_resource_cleanup
+---------------------------------------------------------------------
+
+(1 row)
+
 \c - - - :worker_2_port
 SET search_path TO local_shard_execution_dropped_column;
 -- show the dropped columns
@@ -331,6 +431,108 @@ execute p3(8);
 NOTICE:  executing the command locally: INSERT INTO local_shard_execution_dropped_column.t1_2460000 AS citus_table_alias (c) VALUES (8), (8), (8), (8), (8), (8), (8), (8), (8), (8), (8), (8), (8), (8) ON CONFLICT DO NOTHING
 execute p3(8);
 NOTICE:  executing the command locally: INSERT INTO local_shard_execution_dropped_column.t1_2460000 AS citus_table_alias (c) VALUES (8), (8), (8), (8), (8), (8), (8), (8), (8), (8), (8), (8), (8), (8) ON CONFLICT DO NOTHING
+-- Test that "Avoid deparse and planning of shard query for local execution"
+-- does not take the fast path of modifying the parse tree with the shard OID
+-- for this scenario (rebalance) also.
+--
+-- (*) https://github.com/citusdata/citus/pull/8035
+SET client_min_messages to DEBUG2;
+prepare p4(int) as SELECT count(*) FROM t1 WHERE c = 8 and 5 = $1 GROUP BY c;
+execute p4(5);
+DEBUG:  Distributed planning for a fast-path router query
+DEBUG:  Creating router plan
+DEBUG:  Router planner fast path cannot modify parse tree for local execution: shard table "local_shard_execution_dropped_column.t1_2460000" does not match the distributed table "local_shard_execution_dropped_column.t1"
+DEBUG:  query has a single distribution column value: 8
+NOTICE:  executing the command locally: SELECT count(*) AS count FROM local_shard_execution_dropped_column.t1_2460000 t1 WHERE ((c OPERATOR(pg_catalog.=) 8) AND (5 OPERATOR(pg_catalog.=) $1)) GROUP BY c
+ count
+---------------------------------------------------------------------
+     1
+(1 row)
+
+execute p4(5);
+DEBUG:  Distributed planning for a fast-path router query
+DEBUG:  Creating router plan
+DEBUG:  Router planner fast path cannot modify parse tree for local execution: shard table "local_shard_execution_dropped_column.t1_2460000" does not match the distributed table "local_shard_execution_dropped_column.t1"
+DEBUG:  query has a single distribution column value: 8
+NOTICE:  executing the command locally: SELECT count(*) AS count FROM local_shard_execution_dropped_column.t1_2460000 t1 WHERE ((c OPERATOR(pg_catalog.=) 8) AND (5 OPERATOR(pg_catalog.=) $1)) GROUP BY c
+ count
+---------------------------------------------------------------------
+     1
+(1 row)
+
+execute p4(5);
+DEBUG:  Distributed planning for a fast-path router query
+DEBUG:  Creating router plan
+DEBUG:  Router planner fast path cannot modify parse tree for local execution: shard table "local_shard_execution_dropped_column.t1_2460000" does not match the distributed table "local_shard_execution_dropped_column.t1"
+DEBUG:  query has a single distribution column value: 8
+NOTICE:  executing the command locally: SELECT count(*) AS count FROM local_shard_execution_dropped_column.t1_2460000 t1 WHERE ((c OPERATOR(pg_catalog.=) 8) AND (5 OPERATOR(pg_catalog.=) $1)) GROUP BY c
+ count
+---------------------------------------------------------------------
+     1
+(1 row)
+
+execute p4(5);
+DEBUG:  Distributed planning for a fast-path router query
+DEBUG:  Creating router plan
+DEBUG:  Router planner fast path cannot modify parse tree for local execution: shard table "local_shard_execution_dropped_column.t1_2460000" does not match the distributed table "local_shard_execution_dropped_column.t1"
+DEBUG:  query has a single distribution column value: 8
+NOTICE:  executing the command locally: SELECT count(*) AS count FROM local_shard_execution_dropped_column.t1_2460000 t1 WHERE ((c OPERATOR(pg_catalog.=) 8) AND (5 OPERATOR(pg_catalog.=) $1)) GROUP BY c
+ count
+---------------------------------------------------------------------
+     1
+(1 row)
+
+execute p4(5);
+DEBUG:  Distributed planning for a fast-path router query
+DEBUG:  Creating router plan
+DEBUG:  Router planner fast path cannot modify parse tree for local execution: shard table "local_shard_execution_dropped_column.t1_2460000" does not match the distributed table "local_shard_execution_dropped_column.t1"
+DEBUG:  query has a single distribution column value: 8
+NOTICE:  executing the command locally: SELECT count(*) AS count FROM local_shard_execution_dropped_column.t1_2460000 t1 WHERE ((c OPERATOR(pg_catalog.=) 8) AND (5 OPERATOR(pg_catalog.=) $1)) GROUP BY c
+ count
+---------------------------------------------------------------------
+     1
+(1 row)
+
+execute p4(5);
+DEBUG:  Distributed planning for a fast-path router query
+DEBUG:  Creating router plan
+DEBUG:  Router planner fast path cannot modify parse tree for local execution: shard table "local_shard_execution_dropped_column.t1_2460000" does not match the distributed table "local_shard_execution_dropped_column.t1"
+DEBUG:  query has a single distribution column value: 8
+NOTICE:  executing the command locally: SELECT count(*) AS count FROM local_shard_execution_dropped_column.t1_2460000 t1 WHERE ((c OPERATOR(pg_catalog.=) 8) AND (5 OPERATOR(pg_catalog.=) $1)) GROUP BY c
+ count
+---------------------------------------------------------------------
+     1
+(1 row)
+
+execute p4(5);
+NOTICE:  executing the command locally: SELECT count(*) AS count FROM local_shard_execution_dropped_column.t1_2460000 t1 WHERE ((c OPERATOR(pg_catalog.=) 8) AND (5 OPERATOR(pg_catalog.=) $1)) GROUP BY c
+ count
+---------------------------------------------------------------------
+     1
+(1 row)
+
+execute p4(5);
+NOTICE:  executing the command locally: SELECT count(*) AS count FROM local_shard_execution_dropped_column.t1_2460000 t1 WHERE ((c OPERATOR(pg_catalog.=) 8) AND (5 OPERATOR(pg_catalog.=) $1)) GROUP BY c
+ count
+---------------------------------------------------------------------
+     1
+(1 row)
+
+execute p4(5);
+NOTICE:  executing the command locally: SELECT count(*) AS count FROM local_shard_execution_dropped_column.t1_2460000 t1 WHERE ((c OPERATOR(pg_catalog.=) 8) AND (5 OPERATOR(pg_catalog.=) $1)) GROUP BY c
+ count
+---------------------------------------------------------------------
+     1
+(1 row)
+
+execute p4(5);
+NOTICE:  executing the command locally: SELECT count(*) AS count FROM local_shard_execution_dropped_column.t1_2460000 t1 WHERE ((c OPERATOR(pg_catalog.=) 8) AND (5 OPERATOR(pg_catalog.=) $1)) GROUP BY c
+ count
+---------------------------------------------------------------------
+     1
+(1 row)
+
+RESET client_min_messages;
 \c - - - :master_port
 DROP SCHEMA local_shard_execution_dropped_column CASCADE;
 NOTICE:  drop cascades to table local_shard_execution_dropped_column.t1

src/test/regress/expected/merge_schema_sharding.out

@@ -192,7 +192,9 @@ DEBUG:  A mix of distributed and citus-local table, routable query is not possib
 DEBUG:  Creating MERGE repartition plan
 DEBUG:  Distributed planning for a fast-path router query
 DEBUG:  Creating router plan
+DEBUG:  Fast-path router query: created local execution plan to avoid deparse and compile of shard query
 DEBUG:  Collect source query results on coordinator
+DEBUG:  Local executor: Using task's cached local plan for task 0
 DEBUG:  Create a MERGE task list that needs to be routed
 DEBUG:  <Deparsed MERGE query: MERGE INTO schema_shard_table1.nullkey_c1_t1_4005006 citus_table_alias USING (SELECT intermediate_result.a, intermediate_result.b FROM read_intermediate_result('merge_into_XXX_4005006'::text, 'binary'::citus_copy_format) intermediate_result(a integer, b integer)) citus_local_table ON (citus_table_alias.a OPERATOR(pg_catalog.=) citus_local_table.a) WHEN MATCHED THEN UPDATE SET b = citus_local_table.b>
 DEBUG:  distributed statement: MERGE INTO schema_shard_table1.nullkey_c1_t1_4005006 citus_table_alias USING (SELECT intermediate_result.a, intermediate_result.b FROM read_intermediate_result('merge_into_XXX_4005006'::text, 'binary'::citus_copy_format) intermediate_result(a integer, b integer)) citus_local_table ON (citus_table_alias.a OPERATOR(pg_catalog.=) citus_local_table.a) WHEN MATCHED THEN UPDATE SET b = citus_local_table.b

src/test/regress/expected/multi_explain.out

@@ -2492,15 +2492,15 @@ Custom Scan (Citus Adaptive) (actual rows=1 loops=1)
   ->  Distributed Subplan XXX_1
         Intermediate Data Size: 100 bytes
         Result destination: Write locally
-        ->  Custom Scan (Citus Adaptive) (actual rows=20 loops=1)
+        ->  Custom Scan (Citus Adaptive) (actual rows=10 loops=1)
               Task Count: 4
-              Tuple data received from nodes: 160 bytes
+              Tuple data received from nodes: 80 bytes
               Tasks Shown: One of 4
               ->  Task
-                    Tuple data received from node: 64 bytes
+                    Tuple data received from node: 32 bytes
                     Node: host=localhost port=xxxxx dbname=regression
-                    ->  Insert on dist_table_570017 citus_table_alias (actual rows=8 loops=1)
+                    ->  Insert on dist_table_570017 citus_table_alias (actual rows=4 loops=1)
-                          ->  Seq Scan on dist_table_570017 dist_table (actual rows=8 loops=1)
+                          ->  Seq Scan on dist_table_570017 dist_table (actual rows=4 loops=1)
                                 Filter: (a IS NOT NULL)
   ->  Distributed Subplan XXX_2
         Intermediate Data Size: 150 bytes
@@ -3228,6 +3228,159 @@ Custom Scan (Citus Adaptive) (actual rows=0 loops=1)
                 ->  Update on tbl_570036 tbl (actual rows=0 loops=1)
                       ->  Seq Scan on tbl_570036 tbl (actual rows=0 loops=1)
                             Filter: (a = 1)
+-- EXPLAIN ANALYZE shouldn't execute SubPlans twice (bug #4212)
+SET search_path TO multi_explain;
+CREATE TABLE test_subplans (x int primary key, y int);
+SELECT create_distributed_table('test_subplans','x');
+
+EXPLAIN (COSTS off, ANALYZE on, TIMING off, SUMMARY off)
+WITH a AS (INSERT INTO test_subplans VALUES (1,2) RETURNING *)
+SELECT * FROM a;
+Custom Scan (Citus Adaptive) (actual rows=1 loops=1)
+  ->  Distributed Subplan XXX_1
+        Intermediate Data Size: 18 bytes
+        Result destination: Write locally
+        ->  Custom Scan (Citus Adaptive) (actual rows=1 loops=1)
+              Task Count: 1
+              Tuple data received from nodes: 16 bytes
+              Tasks Shown: All
+              ->  Task
+                    Tuple data received from node: 16 bytes
+                    Node: host=localhost port=xxxxx dbname=regression
+                    ->  Insert on test_subplans_570038 (actual rows=1 loops=1)
+                          ->  Result (actual rows=1 loops=1)
+  Task Count: 1
+  Tuple data received from nodes: 8 bytes
+  Tasks Shown: All
+  ->  Task
+        Tuple data received from node: 8 bytes
+        Node: host=localhost port=xxxxx dbname=regression
+        ->  Function Scan on read_intermediate_result intermediate_result (actual rows=1 loops=1)
+-- Only one row must exist
+SELECT * FROM test_subplans;
+1|2
+-- Will fail with duplicate pk
+EXPLAIN (COSTS off, ANALYZE on, TIMING off, SUMMARY off)
+WITH a AS (INSERT INTO test_subplans VALUES (1,2) RETURNING *)
+SELECT * FROM a;
+ERROR:  duplicate key value violates unique constraint "test_subplans_pkey_570038"
+DETAIL:  Key (x)=(1) already exists.
+CONTEXT:  while executing command on localhost:xxxxx
+-- Test JSON format
+TRUNCATE test_subplans;
+EXPLAIN (FORMAT JSON, COSTS off, ANALYZE on, TIMING off, SUMMARY off)
+WITH a AS (INSERT INTO test_subplans VALUES (1,2) RETURNING *)
+SELECT * FROM a;
+[
+  {
+    "Plan": {
+      "Node Type": "Custom Scan",
+      "Custom Plan Provider": "Citus Adaptive",
+      "Parallel Aware": false,
+      "Async Capable": false,
+      "Actual Rows": 1,
+      "Actual Loops": 1,
+      "Distributed Query": {
+        "Subplans": [
+          {
+            "Intermediate Data Size": "18 bytes",
+            "Result destination": "Write locally",
+            "PlannedStmt": [
+              {
+                "Plan": {
+                  "Node Type": "Custom Scan",
+                  "Custom Plan Provider": "Citus Adaptive",
+                  "Parallel Aware": false,
+                  "Async Capable": false,
+                  "Actual Rows": 1,
+                  "Actual Loops": 1,
+                  "Distributed Query": {
+                    "Job": {
+                      "Task Count": 1,
+                      "Tuple data received from nodes": "16 bytes",
+                      "Tasks Shown": "All",
+                      "Tasks": [
+                        {
+                          "Tuple data received from node": "16 bytes",
+                          "Node": "host=localhost port=xxxxx dbname=regression",
+                          "Remote Plan": [
+                            [
+                              {
+                                "Plan": {
+                                  "Node Type": "ModifyTable",
+                                  "Operation": "Insert",
+                                  "Parallel Aware": false,
+                                  "Async Capable": false,
+                                  "Relation Name": "test_subplans_570038",
+                                  "Alias": "test_subplans_570038",
+                                  "Actual Rows": 1,
+                                  "Actual Loops": 1,
+                                  "Plans": [
+                                    {
+                                      "Node Type": "Result",
+                                      "Parent Relationship": "Outer",
+                                      "Parallel Aware": false,
+                                      "Async Capable": false,
+                                      "Actual Rows": 1,
+                                      "Actual Loops": 1
+                                    }
+                                  ]
+                                },
+                                "Triggers": [
+                                ]
+                              }
+                            ]
+
+                          ]
+                        }
+                      ]
+                    }
+                  }
+                },
+                "Triggers": [
+                ]
+              }
+            ]
+          }
+        ],
+        "Job": {
+          "Task Count": 1,
+          "Tuple data received from nodes": "8 bytes",
+          "Tasks Shown": "All",
+          "Tasks": [
+            {
+              "Tuple data received from node": "8 bytes",
+              "Node": "host=localhost port=xxxxx dbname=regression",
+              "Remote Plan": [
+                [
+                  {
+                    "Plan": {
+                      "Node Type": "Function Scan",
+                      "Parallel Aware": false,
+                      "Async Capable": false,
+                      "Function Name": "read_intermediate_result",
+                      "Alias": "intermediate_result",
+                      "Actual Rows": 1,
+                      "Actual Loops": 1
+                    },
+                    "Triggers": [
+                    ]
+                  }
+                ]
+
+              ]
+            }
+          ]
+        }
+      }
+    },
+    "Triggers": [
+    ]
+  }
+]
+-- Only one row must exist
+SELECT * FROM test_subplans;
+1|2
 -- check when auto explain + analyze is enabled, we do not allow local execution.
 CREATE SCHEMA test_auto_explain;
 SET search_path TO 'test_auto_explain';

src/test/regress/expected/multi_explain_0.out

@@ -2484,15 +2484,15 @@ Custom Scan (Citus Adaptive) (actual rows=1 loops=1)
   ->  Distributed Subplan XXX_1
         Intermediate Data Size: 100 bytes
         Result destination: Write locally
-        ->  Custom Scan (Citus Adaptive) (actual rows=20 loops=1)
+        ->  Custom Scan (Citus Adaptive) (actual rows=10 loops=1)
               Task Count: 4
-              Tuple data received from nodes: 160 bytes
+              Tuple data received from nodes: 80 bytes
               Tasks Shown: One of 4
               ->  Task
-                    Tuple data received from node: 64 bytes
+                    Tuple data received from node: 32 bytes
                     Node: host=localhost port=xxxxx dbname=regression
-                    ->  Insert on dist_table_570017 citus_table_alias (actual rows=8 loops=1)
+                    ->  Insert on dist_table_570017 citus_table_alias (actual rows=4 loops=1)
-                          ->  Seq Scan on dist_table_570017 dist_table (actual rows=8 loops=1)
+                          ->  Seq Scan on dist_table_570017 dist_table (actual rows=4 loops=1)
                                 Filter: (a IS NOT NULL)
   ->  Distributed Subplan XXX_2
         Intermediate Data Size: 150 bytes
@@ -3217,6 +3217,159 @@ Custom Scan (Citus Adaptive) (actual rows=0 loops=1)
                 ->  Update on tbl_570036 tbl (actual rows=0 loops=1)
                       ->  Seq Scan on tbl_570036 tbl (actual rows=0 loops=1)
                             Filter: (a = 1)
+-- EXPLAIN ANALYZE shouldn't execute SubPlans twice (bug #4212)
+SET search_path TO multi_explain;
+CREATE TABLE test_subplans (x int primary key, y int);
+SELECT create_distributed_table('test_subplans','x');
+
+EXPLAIN (COSTS off, ANALYZE on, TIMING off, SUMMARY off)
+WITH a AS (INSERT INTO test_subplans VALUES (1,2) RETURNING *)
+SELECT * FROM a;
+Custom Scan (Citus Adaptive) (actual rows=1 loops=1)
+  ->  Distributed Subplan XXX_1
+        Intermediate Data Size: 18 bytes
+        Result destination: Write locally
+        ->  Custom Scan (Citus Adaptive) (actual rows=1 loops=1)
+              Task Count: 1
+              Tuple data received from nodes: 16 bytes
+              Tasks Shown: All
+              ->  Task
+                    Tuple data received from node: 16 bytes
+                    Node: host=localhost port=xxxxx dbname=regression
+                    ->  Insert on test_subplans_570038 (actual rows=1 loops=1)
+                          ->  Result (actual rows=1 loops=1)
+  Task Count: 1
+  Tuple data received from nodes: 8 bytes
+  Tasks Shown: All
+  ->  Task
+        Tuple data received from node: 8 bytes
+        Node: host=localhost port=xxxxx dbname=regression
+        ->  Function Scan on read_intermediate_result intermediate_result (actual rows=1 loops=1)
+-- Only one row must exist
+SELECT * FROM test_subplans;
+1|2
+-- Will fail with duplicate pk
+EXPLAIN (COSTS off, ANALYZE on, TIMING off, SUMMARY off)
+WITH a AS (INSERT INTO test_subplans VALUES (1,2) RETURNING *)
+SELECT * FROM a;
+ERROR:  duplicate key value violates unique constraint "test_subplans_pkey_570038"
+DETAIL:  Key (x)=(1) already exists.
+CONTEXT:  while executing command on localhost:xxxxx
+-- Test JSON format
+TRUNCATE test_subplans;
+EXPLAIN (FORMAT JSON, COSTS off, ANALYZE on, TIMING off, SUMMARY off)
+WITH a AS (INSERT INTO test_subplans VALUES (1,2) RETURNING *)
+SELECT * FROM a;
+[
+  {
+    "Plan": {
+      "Node Type": "Custom Scan",
+      "Custom Plan Provider": "Citus Adaptive",
+      "Parallel Aware": false,
+      "Async Capable": false,
+      "Actual Rows": 1,
+      "Actual Loops": 1,
+      "Distributed Query": {
+        "Subplans": [
+          {
+            "Intermediate Data Size": "18 bytes",
+            "Result destination": "Write locally",
+            "PlannedStmt": [
+              {
+                "Plan": {
+                  "Node Type": "Custom Scan",
+                  "Custom Plan Provider": "Citus Adaptive",
+                  "Parallel Aware": false,
+                  "Async Capable": false,
+                  "Actual Rows": 1,
+                  "Actual Loops": 1,
+                  "Distributed Query": {
+                    "Job": {
+                      "Task Count": 1,
+                      "Tuple data received from nodes": "16 bytes",
+                      "Tasks Shown": "All",
+                      "Tasks": [
+                        {
+                          "Tuple data received from node": "16 bytes",
+                          "Node": "host=localhost port=xxxxx dbname=regression",
+                          "Remote Plan": [
+                            [
+                              {
+                                "Plan": {
+                                  "Node Type": "ModifyTable",
+                                  "Operation": "Insert",
+                                  "Parallel Aware": false,
+                                  "Async Capable": false,
+                                  "Relation Name": "test_subplans_570038",
+                                  "Alias": "test_subplans_570038",
+                                  "Actual Rows": 1,
+                                  "Actual Loops": 1,
+                                  "Plans": [
+                                    {
+                                      "Node Type": "Result",
+                                      "Parent Relationship": "Outer",
+                                      "Parallel Aware": false,
+                                      "Async Capable": false,
+                                      "Actual Rows": 1,
+                                      "Actual Loops": 1
+                                    }
+                                  ]
+                                },
+                                "Triggers": [
+                                ]
+                              }
+                            ]
+
+                          ]
+                        }
+                      ]
+                    }
+                  }
+                },
+                "Triggers": [
+                ]
+              }
+            ]
+          }
+        ],
+        "Job": {
+          "Task Count": 1,
+          "Tuple data received from nodes": "8 bytes",
+          "Tasks Shown": "All",
+          "Tasks": [
+            {
+              "Tuple data received from node": "8 bytes",
+              "Node": "host=localhost port=xxxxx dbname=regression",
+              "Remote Plan": [
+                [
+                  {
+                    "Plan": {
+                      "Node Type": "Function Scan",
+                      "Parallel Aware": false,
+                      "Async Capable": false,
+                      "Function Name": "read_intermediate_result",
+                      "Alias": "intermediate_result",
+                      "Actual Rows": 1,
+                      "Actual Loops": 1
+                    },
+                    "Triggers": [
+                    ]
+                  }
+                ]
+
+              ]
+            }
+          ]
+        }
+      }
+    },
+    "Triggers": [
+    ]
+  }
+]
+-- Only one row must exist
+SELECT * FROM test_subplans;
+1|2
 -- check when auto explain + analyze is enabled, we do not allow local execution.
 CREATE SCHEMA test_auto_explain;
 SET search_path TO 'test_auto_explain';

src/test/regress/expected/multi_extension.out

@@ -1503,7 +1503,9 @@ ALTER EXTENSION citus UPDATE TO '13.2-1';
 SELECT * FROM multi_extension.print_extension_changes();
  previous_object | current_object
 ---------------------------------------------------------------------
-(0 rows)
+ function worker_last_saved_explain_analyze() TABLE(explain_analyze_output text, execution_duration double precision) |
+ | function worker_last_saved_explain_analyze() TABLE(explain_analyze_output text, execution_duration double precision, execution_ntuples double precision, execution_nloops double precision)
+(2 rows)
 
 DROP TABLE multi_extension.prev_objects, multi_extension.extension_diff;
 -- show running version

src/test/regress/expected/multi_modifications.out

@@ -330,6 +330,12 @@ UPDATE limit_orders SET (kind, limit_price) = ('buy', 999) WHERE id = 246 RETURN
  246 | GM     |        30 | Mon Jul 02 16:32:15 2007 | buy  |         999
 (1 row)
 
+UPDATE limit_orders SET (kind, limit_price) = (SELECT 'buy'::order_side, 999) WHERE id = 246 RETURNING *;
+ id  | symbol | bidder_id |        placed_at         | kind | limit_price
+---------------------------------------------------------------------
+ 246 | GM     |        30 | Mon Jul 02 16:32:15 2007 | buy  |         999
+(1 row)
+
 -- Test that on unique contraint violations, we fail fast
 \set VERBOSITY terse
 INSERT INTO limit_orders VALUES (275, 'ADR', 140, '2007-07-02 16:32:15', 'sell', 43.67);
@@ -435,6 +441,8 @@ UPDATE limit_orders SET limit_price = 0.00 FROM bidders
 -- should succeed with a CTE
 WITH deleted_orders AS (INSERT INTO limit_orders VALUES (399, 'PDR', 14, '2017-07-02 16:32:15', 'sell', 43))
 UPDATE limit_orders SET symbol = 'GM';
+WITH deleted_orders AS (INSERT INTO limit_orders SELECT 400, 'PDR', 14, '2017-07-02 16:32:15', 'sell', 43)
+UPDATE limit_orders SET symbol = 'GM';
 SELECT symbol, bidder_id FROM limit_orders WHERE id = 246;
  symbol | bidder_id
 ---------------------------------------------------------------------
@@ -927,6 +935,17 @@ SELECT * FROM summary_table ORDER BY id;
   2 |       400 | 450.0000000000000000 |       |
 (2 rows)
 
+-- try different order of update targets
+UPDATE summary_table SET (average_value, min_value) =
+ 	(SELECT avg(value), min(value) FROM raw_table WHERE id = 2)
+WHERE id = 2;
+SELECT * FROM summary_table ORDER BY id;
+ id | min_value |    average_value     | count | uniques
+---------------------------------------------------------------------
+  1 |           | 200.0000000000000000 |       |
+  2 |       400 | 450.0000000000000000 |       |
+(2 rows)
+
 UPDATE summary_table SET min_value = 100
 	WHERE id IN (SELECT id FROM raw_table WHERE id = 1 and value > 100) AND id = 1;
 SELECT * FROM summary_table ORDER BY id;
@@ -1103,6 +1122,16 @@ SELECT * FROM reference_summary_table ORDER BY id;
   2 |       400 | 450.0000000000000000 |       |
 (2 rows)
 
+UPDATE reference_summary_table SET (average_value, min_value) =
+	(SELECT avg(value), min(value) FROM reference_raw_table WHERE id = 2)
+WHERE id = 2;
+SELECT * FROM reference_summary_table ORDER BY id;
+ id | min_value |    average_value     | count | uniques
+---------------------------------------------------------------------
+  1 |           | 200.0000000000000000 |       |
+  2 |       400 | 450.0000000000000000 |       |
+(2 rows)
+
 -- no need partition colum equalities on reference tables
 UPDATE reference_summary_table SET (count) =
 	(SELECT id AS inner_id FROM reference_raw_table WHERE value = 500)
@@ -1329,5 +1358,14 @@ DROP TABLE raw_table;
 DROP TABLE summary_table;
 DROP TABLE reference_raw_table;
 DROP TABLE reference_summary_table;
+DROP TABLE limit_orders;
+DROP TABLE multiple_hash;
+DROP TABLE range_partitioned;
+DROP TABLE append_partitioned;
+DROP TABLE bidders;
+DROP FUNCTION stable_append;
+DROP FUNCTION immutable_append;
+DROP FUNCTION temp_strict_func;
+DROP TYPE order_side;
 DROP SCHEMA multi_modifications CASCADE;
 NOTICE:  drop cascades to table multi_modifications.local

src/test/regress/expected/multi_subquery_in_where_clause.out

@@ -1,7 +1,7 @@
 --
 -- multi subquery in where queries aims to expand existing subquery pushdown
 -- regression tests to cover more cases specifically subqueries in WHERE clause
--- the tables that are used depends to multi_insert_select_behavioral_analytics_create_table.sql
+-- the tables that are used depends to multi_behavioral_analytics_create_table.sql
 --
 -- We don't need shard id sequence here, so commented out to prevent conflicts with concurrent tests
 -- subqueries in WHERE with greater operator

src/test/regress/expected/multi_subquery_misc.out

@@ -2,7 +2,7 @@
 --   (i)   Prepared statements
 --   (ii)  PL/PGSQL functions
 --   (iii) SQL functions
--- the tables that are used depends to multi_insert_select_behavioral_analytics_create_table.sql
+-- the tables that are used depends to multi_behavioral_analytics_create_table.sql
 -- We don't need shard id sequence here, so commented out to prevent conflicts with concurrent tests
 SET citus.enable_router_execution TO false;
 PREPARE prepared_subquery_1 AS
@@ -352,6 +352,7 @@ ORDER BY 2 DESC;
 -- Similar to the above queries, but
 -- this time the joins are not removed because
 -- target list contains all the entries
+SET citus.enable_router_execution TO true;
 SELECT
     *
 FROM users_table t1

src/test/regress/expected/multi_subquery_union.out

@@ -1,7 +1,7 @@
 --
 -- multi subquery toplevel union queries aims to expand existing subquery pushdown
 -- regression tests to cover more cases
--- the tables that are used depends to multi_insert_select_behavioral_analytics_create_table.sql
+-- the tables that are used depends to multi_behavioral_analytics_create_table.sql
 -- We don't need shard id sequence here, so commented out to prevent conflicts with concurrent tests
 -- SET citus.next_shard_id TO 1400000;
 -- a very simple union query
@@ -1246,5 +1246,3 @@ SELECT user_id FROM users_table
 UNION SELECT u.user_id FROM users_table, users_udf() u;
 ERROR:  cannot perform distributed planning on this query because parameterized queries for SQL functions referencing distributed tables are not supported
 HINT:  Consider using PL/pgSQL functions instead.
-DROP TABLE events_reference_table;
-DROP TABLE users_reference_table;

src/test/regress/expected/multi_update_select.out

@@ -0,0 +1,717 @@
+CREATE SCHEMA multi_update_select;
+SET search_path TO multi_update_select;
+SET citus.next_shard_id TO 751000;
+-- specific tests related to get_update_query_targetlist_def
+-- we test only queries with sublinks, like:
+-- ( ... SET (...) = (SELECT ...))
+-- Reference tables
+CREATE TABLE test_ref_indirection (
+    id bigint primary key
+  , col_bool bool , col_date date , col_int integer , col_text text
+  );
+SELECT create_reference_table('test_ref_indirection');
+ create_reference_table
+---------------------------------------------------------------------
+
+(1 row)
+
+CREATE TABLE test_ref_indirection_new (
+    id bigint primary key
+  , col_bool bool , col_date date , col_int integer , col_text text
+  );
+SELECT create_reference_table('test_ref_indirection_new');
+ create_reference_table
+---------------------------------------------------------------------
+
+(1 row)
+
+-- Distributed tables
+CREATE TABLE test_dist_indirection (
+    id bigint primary key
+  , col_bool bool , col_date date , col_int integer , col_text text
+  );
+SELECT create_distributed_table('test_dist_indirection', 'id');
+ create_distributed_table
+---------------------------------------------------------------------
+
+(1 row)
+
+CREATE TABLE test_dist_indirection_new (
+    id bigint primary key
+  , col_bool bool , col_date date , col_int integer , col_text text
+  );
+SELECT create_distributed_table('test_dist_indirection_new', 'id');
+ create_distributed_table
+---------------------------------------------------------------------
+
+(1 row)
+
+-- those should work:
+INSERT INTO test_ref_indirection (id, col_bool, col_date, col_int, col_text)
+    SELECT 1, true, '1970-01-01'::date, 1, 'one';
+INSERT INTO test_dist_indirection (id, col_bool, col_date, col_int, col_text)
+    SELECT 1, true, '1970-01-01'::date, 1, 'one';
+INSERT INTO test_ref_indirection (id, col_text, col_bool, col_date, col_int)
+    SELECT 2, 'two', false, '1970-01-01'::date, 2;
+INSERT INTO test_dist_indirection (id, col_text, col_bool, col_date, col_int)
+    SELECT 2, 'two', false, '1970-01-01'::date, 2;
+INSERT INTO test_ref_indirection SELECT 3, false, '1970-01-01'::date, 0, 'empty';
+INSERT INTO test_dist_indirection SELECT 3, false, '1970-01-01'::date, 0, 'empty';
+INSERT INTO test_ref_indirection SELECT 4, false, '1970-01-01'::date, 0, 'empty';
+INSERT INTO test_dist_indirection SELECT 4, false, '1970-01-01'::date, 0, 'empty';
+INSERT INTO test_ref_indirection_new SELECT * FROM test_ref_indirection;
+INSERT INTO test_dist_indirection_new SELECT * FROM test_dist_indirection;
+SELECT * FROM test_ref_indirection ORDER BY id;
+ id | col_bool |  col_date  | col_int | col_text
+---------------------------------------------------------------------
+  1 | t        | 01-01-1970 |       1 | one
+  2 | f        | 01-01-1970 |       2 | two
+  3 | f        | 01-01-1970 |       0 | empty
+  4 | f        | 01-01-1970 |       0 | empty
+(4 rows)
+
+SELECT * FROM test_dist_indirection ORDER BY id;
+ id | col_bool |  col_date  | col_int | col_text
+---------------------------------------------------------------------
+  1 | t        | 01-01-1970 |       1 | one
+  2 | f        | 01-01-1970 |       2 | two
+  3 | f        | 01-01-1970 |       0 | empty
+  4 | f        | 01-01-1970 |       0 | empty
+(4 rows)
+
+SELECT * FROM test_ref_indirection_new ORDER BY id;
+ id | col_bool |  col_date  | col_int | col_text
+---------------------------------------------------------------------
+  1 | t        | 01-01-1970 |       1 | one
+  2 | f        | 01-01-1970 |       2 | two
+  3 | f        | 01-01-1970 |       0 | empty
+  4 | f        | 01-01-1970 |       0 | empty
+(4 rows)
+
+SELECT * FROM test_dist_indirection_new ORDER BY id;
+ id | col_bool |  col_date  | col_int | col_text
+---------------------------------------------------------------------
+  1 | t        | 01-01-1970 |       1 | one
+  2 | f        | 01-01-1970 |       2 | two
+  3 | f        | 01-01-1970 |       0 | empty
+  4 | f        | 01-01-1970 |       0 | empty
+(4 rows)
+
+-- now UPDATEs
+UPDATE test_ref_indirection
+    SET (col_bool, col_date, col_int, col_text)
+        = (SELECT true, '1970-01-01'::date, 1, 'ok')
+RETURNING *;
+ id | col_bool |  col_date  | col_int | col_text
+---------------------------------------------------------------------
+  1 | t        | 01-01-1970 |       1 | ok
+  2 | t        | 01-01-1970 |       1 | ok
+  3 | t        | 01-01-1970 |       1 | ok
+  4 | t        | 01-01-1970 |       1 | ok
+(4 rows)
+
+UPDATE test_dist_indirection
+    SET (col_bool, col_date, col_int, col_text)
+        = (SELECT true, '1970-01-01'::date, 1, 'ok')
+RETURNING *;
+ id | col_bool |  col_date  | col_int | col_text
+---------------------------------------------------------------------
+  1 | t        | 01-01-1970 |       1 | ok
+  2 | t        | 01-01-1970 |       1 | ok
+  3 | t        | 01-01-1970 |       1 | ok
+  4 | t        | 01-01-1970 |       1 | ok
+(4 rows)
+
+UPDATE test_ref_indirection
+    SET (col_bool, col_date)  = (select false, '1971-01-01'::date)
+      , (col_int, col_text) = (select 2, '2 ok')
+RETURNING *;
+ id | col_bool |  col_date  | col_int | col_text
+---------------------------------------------------------------------
+  1 | f        | 01-01-1971 |       2 | 2 ok
+  2 | f        | 01-01-1971 |       2 | 2 ok
+  3 | f        | 01-01-1971 |       2 | 2 ok
+  4 | f        | 01-01-1971 |       2 | 2 ok
+(4 rows)
+
+UPDATE test_dist_indirection
+    SET (col_bool, col_date)  = (select false, '1971-01-01'::date)
+      , (col_int, col_text) = (select 2, '2 ok')
+RETURNING *;
+ id | col_bool |  col_date  | col_int | col_text
+---------------------------------------------------------------------
+  1 | f        | 01-01-1971 |       2 | 2 ok
+  2 | f        | 01-01-1971 |       2 | 2 ok
+  3 | f        | 01-01-1971 |       2 | 2 ok
+  4 | f        | 01-01-1971 |       2 | 2 ok
+(4 rows)
+
+UPDATE test_ref_indirection
+    SET (col_bool, col_int)  = (select true, 3)
+      , (col_text) = (select '3 ok')
+RETURNING *;
+ id | col_bool |  col_date  | col_int | col_text
+---------------------------------------------------------------------
+  1 | t        | 01-01-1971 |       3 | 3 ok
+  2 | t        | 01-01-1971 |       3 | 3 ok
+  3 | t        | 01-01-1971 |       3 | 3 ok
+  4 | t        | 01-01-1971 |       3 | 3 ok
+(4 rows)
+
+UPDATE test_dist_indirection
+    SET (col_bool, col_int)  = (select true, 3)
+      , (col_text) = (select '3 ok')
+RETURNING *;
+ id | col_bool |  col_date  | col_int | col_text
+---------------------------------------------------------------------
+  1 | t        | 01-01-1971 |       3 | 3 ok
+  2 | t        | 01-01-1971 |       3 | 3 ok
+  3 | t        | 01-01-1971 |       3 | 3 ok
+  4 | t        | 01-01-1971 |       3 | 3 ok
+(4 rows)
+
+-- but those should work since 13.X
+UPDATE test_ref_indirection
+    SET (col_date, col_text, col_int, col_bool)
+        = (SELECT '1972-01-01'::date, '4 ok', 4, false)
+RETURNING *;
+ id | col_bool |  col_date  | col_int | col_text
+---------------------------------------------------------------------
+  1 | f        | 01-01-1972 |       4 | 4 ok
+  2 | f        | 01-01-1972 |       4 | 4 ok
+  3 | f        | 01-01-1972 |       4 | 4 ok
+  4 | f        | 01-01-1972 |       4 | 4 ok
+(4 rows)
+
+UPDATE test_dist_indirection
+    SET (col_date, col_text, col_int, col_bool)
+        = (SELECT '1972-01-01'::date, '4 ok', 4, false)
+RETURNING *;
+ id | col_bool |  col_date  | col_int | col_text
+---------------------------------------------------------------------
+  1 | f        | 01-01-1972 |       4 | 4 ok
+  2 | f        | 01-01-1972 |       4 | 4 ok
+  3 | f        | 01-01-1972 |       4 | 4 ok
+  4 | f        | 01-01-1972 |       4 | 4 ok
+(4 rows)
+
+UPDATE test_ref_indirection
+    SET (col_int, col_text)  = (select 5, '5 ok')
+      , (col_bool) = (select true)
+RETURNING *;
+ id | col_bool |  col_date  | col_int | col_text
+---------------------------------------------------------------------
+  1 | t        | 01-01-1972 |       5 | 5 ok
+  2 | t        | 01-01-1972 |       5 | 5 ok
+  3 | t        | 01-01-1972 |       5 | 5 ok
+  4 | t        | 01-01-1972 |       5 | 5 ok
+(4 rows)
+
+UPDATE test_dist_indirection
+    SET (col_int, col_text)  = (select 5, '5 ok')
+      , (col_bool) = (select true)
+RETURNING *;
+ id | col_bool |  col_date  | col_int | col_text
+---------------------------------------------------------------------
+  1 | t        | 01-01-1972 |       5 | 5 ok
+  2 | t        | 01-01-1972 |       5 | 5 ok
+  3 | t        | 01-01-1972 |       5 | 5 ok
+  4 | t        | 01-01-1972 |       5 | 5 ok
+(4 rows)
+
+UPDATE test_ref_indirection
+    SET (col_int, col_date)  = (select 6, '1973-01-01'::date)
+      , (col_text, col_bool) = (select '6 ok', false)
+RETURNING *;
+ id | col_bool |  col_date  | col_int | col_text
+---------------------------------------------------------------------
+  1 | f        | 01-01-1973 |       6 | 6 ok
+  2 | f        | 01-01-1973 |       6 | 6 ok
+  3 | f        | 01-01-1973 |       6 | 6 ok
+  4 | f        | 01-01-1973 |       6 | 6 ok
+(4 rows)
+
+UPDATE test_dist_indirection
+    SET (col_int, col_date)  = (select 6, '1973-01-01'::date)
+      , (col_text, col_bool) = (select '6 ok', false)
+RETURNING *;
+ id | col_bool |  col_date  | col_int | col_text
+---------------------------------------------------------------------
+  1 | f        | 01-01-1973 |       6 | 6 ok
+  2 | f        | 01-01-1973 |       6 | 6 ok
+  3 | f        | 01-01-1973 |       6 | 6 ok
+  4 | f        | 01-01-1973 |       6 | 6 ok
+(4 rows)
+
+UPDATE test_ref_indirection
+    SET (col_int, col_date, col_text)  = (select 7, '1974-01-01'::date, '7 ok')
+      , (col_bool) = (select true)
+RETURNING *;
+ id | col_bool |  col_date  | col_int | col_text
+---------------------------------------------------------------------
+  1 | t        | 01-01-1974 |       7 | 7 ok
+  2 | t        | 01-01-1974 |       7 | 7 ok
+  3 | t        | 01-01-1974 |       7 | 7 ok
+  4 | t        | 01-01-1974 |       7 | 7 ok
+(4 rows)
+
+UPDATE test_dist_indirection
+    SET (col_int, col_date, col_text)  = (select 7, '1974-01-01'::date, '7 ok')
+      , (col_bool) = (select true)
+RETURNING *;
+ id | col_bool |  col_date  | col_int | col_text
+---------------------------------------------------------------------
+  1 | t        | 01-01-1974 |       7 | 7 ok
+  2 | t        | 01-01-1974 |       7 | 7 ok
+  3 | t        | 01-01-1974 |       7 | 7 ok
+  4 | t        | 01-01-1974 |       7 | 7 ok
+(4 rows)
+
+UPDATE test_ref_indirection
+    SET (col_date, col_text)  = (select '1975-01-01'::date, '8 ok')
+      , (col_int) = (select 8)
+      , (col_bool) = (select false)
+RETURNING *;
+ id | col_bool |  col_date  | col_int | col_text
+---------------------------------------------------------------------
+  1 | f        | 01-01-1975 |       8 | 8 ok
+  2 | f        | 01-01-1975 |       8 | 8 ok
+  3 | f        | 01-01-1975 |       8 | 8 ok
+  4 | f        | 01-01-1975 |       8 | 8 ok
+(4 rows)
+
+UPDATE test_dist_indirection
+    SET (col_date, col_text)  = (select '1975-01-01'::date, '8 ok')
+      , (col_int) = (select 8)
+      , (col_bool) = (select false)
+RETURNING *;
+ id | col_bool |  col_date  | col_int | col_text
+---------------------------------------------------------------------
+  1 | f        | 01-01-1975 |       8 | 8 ok
+  2 | f        | 01-01-1975 |       8 | 8 ok
+  3 | f        | 01-01-1975 |       8 | 8 ok
+  4 | f        | 01-01-1975 |       8 | 8 ok
+(4 rows)
+
+--
+-- more restrictive ones, just in case we miss a wrong value
+--
+-- those should work
+UPDATE test_ref_indirection
+    SET (col_bool, col_text) = (SELECT true, '9 ok')
+RETURNING *;
+ id | col_bool |  col_date  | col_int | col_text
+---------------------------------------------------------------------
+  1 | t        | 01-01-1975 |       8 | 9 ok
+  2 | t        | 01-01-1975 |       8 | 9 ok
+  3 | t        | 01-01-1975 |       8 | 9 ok
+  4 | t        | 01-01-1975 |       8 | 9 ok
+(4 rows)
+
+UPDATE test_dist_indirection
+    SET (col_bool, col_text) = (SELECT true, '9 ok')
+RETURNING *;
+ id | col_bool |  col_date  | col_int | col_text
+---------------------------------------------------------------------
+  1 | t        | 01-01-1975 |       8 | 9 ok
+  2 | t        | 01-01-1975 |       8 | 9 ok
+  3 | t        | 01-01-1975 |       8 | 9 ok
+  4 | t        | 01-01-1975 |       8 | 9 ok
+(4 rows)
+
+UPDATE test_ref_indirection
+    SET (col_bool, col_text) = (SELECT false, '10 ok')
+WHERE id = 1
+RETURNING *;
+ id | col_bool |  col_date  | col_int | col_text
+---------------------------------------------------------------------
+  1 | f        | 01-01-1975 |       8 | 10 ok
+(1 row)
+
+UPDATE test_dist_indirection
+    SET (col_bool, col_text) = (SELECT false, '10 ok')
+WHERE id = 1
+RETURNING *;
+ id | col_bool |  col_date  | col_int | col_text
+---------------------------------------------------------------------
+  1 | f        | 01-01-1975 |       8 | 10 ok
+(1 row)
+
+UPDATE test_ref_indirection
+    SET (col_text, col_bool) = (SELECT '11 ok', true)
+RETURNING *;
+ id | col_bool |  col_date  | col_int | col_text
+---------------------------------------------------------------------
+  1 | t        | 01-01-1975 |       8 | 11 ok
+  2 | t        | 01-01-1975 |       8 | 11 ok
+  3 | t        | 01-01-1975 |       8 | 11 ok
+  4 | t        | 01-01-1975 |       8 | 11 ok
+(4 rows)
+
+UPDATE test_dist_indirection
+    SET (col_text, col_bool) = (SELECT '11 ok', true)
+RETURNING *;
+ id | col_bool |  col_date  | col_int | col_text
+---------------------------------------------------------------------
+  1 | t        | 01-01-1975 |       8 | 11 ok
+  2 | t        | 01-01-1975 |       8 | 11 ok
+  3 | t        | 01-01-1975 |       8 | 11 ok
+  4 | t        | 01-01-1975 |       8 | 11 ok
+(4 rows)
+
+UPDATE test_ref_indirection
+    SET (col_text, col_bool) = (SELECT '12 ok', false)
+WHERE id = 2
+RETURNING *;
+ id | col_bool |  col_date  | col_int | col_text
+---------------------------------------------------------------------
+  2 | f        | 01-01-1975 |       8 | 12 ok
+(1 row)
+
+UPDATE test_dist_indirection
+    SET (col_text, col_bool) = (SELECT '12 ok', false)
+WHERE id = 2
+RETURNING *;
+ id | col_bool |  col_date  | col_int | col_text
+---------------------------------------------------------------------
+  2 | f        | 01-01-1975 |       8 | 12 ok
+(1 row)
+
+-- several updates in CTE shoult not work
+with qq3 as (
+    update test_ref_indirection
+    SET (col_text, col_bool)
+      = (SELECT '13', true)
+    where id = 3
+    returning *
+),
+qq4 as (
+    update test_ref_indirection
+    SET (col_text, col_bool)
+      = (SELECT '14', false)
+    where id = 4
+    returning *
+)
+select * from qq3 union all select * from qq4;
+ id | col_bool |  col_date  | col_int | col_text
+---------------------------------------------------------------------
+  3 | t        | 01-01-1975 |       8 | 13
+  4 | f        | 01-01-1975 |       8 | 14
+(2 rows)
+
+with qq3 as (
+    update test_dist_indirection
+    SET (col_text, col_bool)
+      = (SELECT '13', true)
+    where id = 3
+    returning *
+),
+qq4 as (
+    update test_dist_indirection
+    SET (col_text, col_bool)
+      = (SELECT '14', false)
+    where id = 4
+    returning *
+)
+select * from qq3 union all select * from qq4;
+ id | col_bool |  col_date  | col_int | col_text
+---------------------------------------------------------------------
+  3 | t        | 01-01-1975 |       8 | 13
+  4 | f        | 01-01-1975 |       8 | 14
+(2 rows)
+
+DROP TABLE test_dist_indirection;
+DROP TABLE test_dist_indirection_new;
+DROP TABLE test_ref_indirection;
+DROP TABLE test_ref_indirection_new;
+-- https://github.com/citusdata/citus/issues/4092
+CREATE TABLE update_test (
+    a   INT DEFAULT 10,
+    b   INT,
+    c   TEXT
+);
+SELECT create_reference_table('update_test');
+ create_reference_table
+---------------------------------------------------------------------
+
+(1 row)
+
+INSERT INTO update_test VALUES (11, 41, 'car');
+INSERT INTO update_test VALUES (100, 20, 'bike');
+INSERT INTO update_test VALUES (100, 20, 'tractor');
+SELECT * FROM update_test;
+  a  | b  |    c
+---------------------------------------------------------------------
+  11 | 41 | car
+ 100 | 20 | bike
+ 100 | 20 | tractor
+(3 rows)
+
+UPDATE update_test
+SET (b,a) = (select a,b from update_test where b = 41 and c = 'car')
+WHERE a = 100 AND b = 20
+RETURNING *;
+ a  | b  |    c
+---------------------------------------------------------------------
+ 41 | 11 | bike
+ 41 | 11 | tractor
+(2 rows)
+
+-- Test that multiple out of order columns and multiple sublinks are handled correctly.
+CREATE TABLE upd2_test (a1 int, b1 int, c1 int, d1 int, e1 int, f1 int, g1 int);
+SELECT create_reference_table('upd2_test');
+ create_reference_table
+---------------------------------------------------------------------
+
+(1 row)
+
+INSERT INTO upd2_test SELECT 1, 1, 1, 1, 1, 1, 1 FROM generate_series(1,5) c(i);
+UPDATE upd2_test set (b1, a1) = (SELECT 200, 100), (g1, f1, e1) = (SELECT 700, 600, 500), (d1, c1) = (SELECT 400, 300);
+SELECT * FROM upd2_test;
+ a1  | b1  | c1  | d1  | e1  | f1  | g1
+---------------------------------------------------------------------
+ 100 | 200 | 300 | 400 | 500 | 600 | 700
+ 100 | 200 | 300 | 400 | 500 | 600 | 700
+ 100 | 200 | 300 | 400 | 500 | 600 | 700
+ 100 | 200 | 300 | 400 | 500 | 600 | 700
+ 100 | 200 | 300 | 400 | 500 | 600 | 700
+(5 rows)
+
+UPDATE upd2_test set (g1, a1) = (SELECT 77, 11), (f1, b1) = (SELECT 66, 22), (e1, c1) = (SELECT 55, 33), (d1) = (SELECT 44);
+SELECT * FROM upd2_test;
+ a1 | b1 | c1 | d1 | e1 | f1 | g1
+---------------------------------------------------------------------
+ 11 | 22 | 33 | 44 | 55 | 66 | 77
+ 11 | 22 | 33 | 44 | 55 | 66 | 77
+ 11 | 22 | 33 | 44 | 55 | 66 | 77
+ 11 | 22 | 33 | 44 | 55 | 66 | 77
+ 11 | 22 | 33 | 44 | 55 | 66 | 77
+(5 rows)
+
+UPDATE upd2_test set (g1, a1) = (SELECT 7, 1), (f1) = (SELECT 6), (c1, e1) = (SELECT 3, 5), (b1) = (SELECT 2), (d1) = (SELECT 4);
+SELECT * FROM upd2_test;
+ a1 | b1 | c1 | d1 | e1 | f1 | g1
+---------------------------------------------------------------------
+  1 |  2 |  3 |  4 |  5 |  6 |  7
+  1 |  2 |  3 |  4 |  5 |  6 |  7
+  1 |  2 |  3 |  4 |  5 |  6 |  7
+  1 |  2 |  3 |  4 |  5 |  6 |  7
+  1 |  2 |  3 |  4 |  5 |  6 |  7
+(5 rows)
+
+-- Test out of order updates on distributed table
+CREATE TABLE dist_test(a1 int, b1 numeric, c1 text, d1 int);
+SELECT create_distributed_table('dist_test', 'a1');
+ create_distributed_table
+---------------------------------------------------------------------
+
+(1 row)
+
+INSERT INTO dist_test VALUES (1, 10.0, 'xxx', 4);
+INSERT INTO dist_test VALUES (1, 10.0, 'xxx', 4);
+INSERT INTO dist_test VALUES (2, 10.0, 'xxx', 4);
+INSERT INTO dist_test VALUES (2, 10.0, 'xxx', 4);
+INSERT INTO dist_test VALUES (3, 10.0, 'xxx', 4);
+INSERT INTO dist_test VALUES (3, 10.0, 'xxx', 4);
+INSERT INTO dist_test VALUES (3, 10.0, 'xxx', 4);
+-- Router plan:
+UPDATE dist_test
+SET (d1, c1, b1) = (SELECT 7, 'tractor', 4.2)
+WHERE a1=1
+RETURNING *;
+ a1 | b1  |   c1    | d1
+---------------------------------------------------------------------
+  1 | 4.2 | tractor |  7
+  1 | 4.2 | tractor |  7
+(2 rows)
+
+-- Pushdown plan:
+UPDATE dist_test
+SET (d1, c1, b1) = (SELECT X, 'car', Y)
+FROM (SELECT r.a * d1 as X, r.b * b1 as Y FROM update_test r, dist_test WHERE r.c=c1) upd
+WHERE dist_test.a1 > 2
+RETURNING *;
+ a1 |  b1  | c1  | d1  |  x  |  y
+---------------------------------------------------------------------
+  3 | 46.2 | car | 287 | 287 | 46.2
+  3 | 46.2 | car | 287 | 287 | 46.2
+  3 | 46.2 | car | 287 | 287 | 46.2
+(3 rows)
+
+-- Test subscripting updates
+CREATE TABLE jsonb_subscript_update (id INT, data JSONB);
+SELECT create_distributed_table('jsonb_subscript_update', 'id');
+ create_distributed_table
+---------------------------------------------------------------------
+
+(1 row)
+
+INSERT INTO jsonb_subscript_update VALUES (1, '{"a": 1}'), (2, '{"a": 2}');
+UPDATE jsonb_subscript_update
+SET data['b'] = updated_vals.b::TEXT::jsonb,
+    data['c'] = updated_vals.c::TEXT::jsonb,
+    data['d'] = updated_vals.d::TEXT::jsonb
+FROM (
+  SELECT id,
+         data['a'] AS a,
+         data['a']::NUMERIC + 1 AS b,
+         data['a']::NUMERIC + 2 AS c,
+         data['a']::NUMERIC + 3 AS d
+  FROM jsonb_subscript_update
+) updated_vals
+WHERE jsonb_subscript_update.id = updated_vals.id;
+SELECT * FROM jsonb_subscript_update ORDER BY 1,2;
+ id |               data
+---------------------------------------------------------------------
+  1 | {"a": 1, "b": 2, "c": 3, "d": 4}
+  2 | {"a": 2, "b": 3, "c": 4, "d": 5}
+(2 rows)
+
+TRUNCATE jsonb_subscript_update;
+INSERT INTO jsonb_subscript_update VALUES (1, '{"a": 1}'), (2, '{"a": 2}');
+-- test router update with jsonb subscript
+UPDATE jsonb_subscript_update
+SET data['b'] = updated_vals.b::TEXT::jsonb,
+    data['c'] = updated_vals.c::TEXT::jsonb,
+    data['d'] = updated_vals.d::TEXT::jsonb
+FROM (
+  SELECT id,
+         data['a'] AS a,
+         data['a']::NUMERIC + 1 AS b,
+         data['a']::NUMERIC + 2 AS c,
+         data['a']::NUMERIC + 3 AS d
+  FROM jsonb_subscript_update
+) updated_vals
+WHERE jsonb_subscript_update.id = updated_vals.id
+    AND jsonb_subscript_update.id = 1;
+SELECT * FROM jsonb_subscript_update WHERE id = 1 ORDER BY 1,2;
+ id |               data
+---------------------------------------------------------------------
+  1 | {"a": 1, "b": 2, "c": 3, "d": 4}
+(1 row)
+
+TRUNCATE jsonb_subscript_update;
+-- Test updates on nested json objects
+INSERT INTO jsonb_subscript_update VALUES (1, '{"a": {"c":20, "d" : 200}}'), (2, '{"a": {"d":10, "c" : 100}}');
+BEGIN;
+UPDATE jsonb_subscript_update
+SET DATA['a']['c'] = (updated_vals.d + updated_vals.a::NUMERIC)::TEXT::JSONB
+FROM
+  (SELECT id,
+          DATA['a']['c'] AS a,
+                   DATA['a']['c']::NUMERIC + 1 AS b,
+                            DATA['a']['c']::NUMERIC + 2 AS c,
+                                     DATA['a']['d']::NUMERIC + 3 AS d
+   FROM jsonb_subscript_update) updated_vals
+WHERE jsonb_subscript_update.id = updated_vals.id;
+SELECT * FROM jsonb_subscript_update ORDER BY 1,2;
+ id |            data
+---------------------------------------------------------------------
+  1 | {"a": {"c": 223, "d": 200}}
+  2 | {"a": {"c": 113, "d": 10}}
+(2 rows)
+
+ROLLBACK;
+BEGIN;
+-- Router plan
+UPDATE jsonb_subscript_update
+SET DATA['a']['c'] = (updated_vals.d + updated_vals.a::NUMERIC)::TEXT::JSONB
+FROM
+  (SELECT id,
+          DATA['a']['c'] AS a,
+                   DATA['a']['c']::NUMERIC + 1 AS b,
+                            DATA['a']['c']::NUMERIC + 2 AS c,
+                                     DATA['a']['d']::NUMERIC + 3 AS d
+   FROM jsonb_subscript_update) updated_vals
+WHERE jsonb_subscript_update.id = updated_vals.id
+    AND jsonb_subscript_update.id = 1;
+SELECT * FROM jsonb_subscript_update WHERE id = 1 ORDER BY 1,2;
+ id |            data
+---------------------------------------------------------------------
+  1 | {"a": {"c": 223, "d": 200}}
+(1 row)
+
+ROLLBACK;
+TRUNCATE jsonb_subscript_update;
+INSERT INTO jsonb_subscript_update VALUES (1, '{"a": 1}'), (2, '{"a": 2}'), (4, '{"a": 4, "b": 10}');
+ALTER TABLE jsonb_subscript_update ADD CONSTRAINT pkey PRIMARY KEY (id, data);
+INSERT INTO jsonb_subscript_update VALUES (1, '{"a": 1}'), (2, '{"a": 2}')
+ON CONFLICT (id, data)
+DO UPDATE SET data['d']=(jsonb_subscript_update.data['a']::INT*100)::TEXT::JSONB,
+              data['b']=(jsonb_subscript_update.data['a']::INT*-100)::TEXT::JSONB;
+SELECT * FROM jsonb_subscript_update ORDER BY 1,2;
+ id |             data
+---------------------------------------------------------------------
+  1 | {"a": 1, "b": -100, "d": 100}
+  2 | {"a": 2, "b": -200, "d": 200}
+  4 | {"a": 4, "b": 10}
+(3 rows)
+
+CREATE TABLE nested_obj_update(id INT, data JSONB, text_col TEXT);
+SELECT create_distributed_table('nested_obj_update', 'id');
+ create_distributed_table
+---------------------------------------------------------------------
+
+(1 row)
+
+INSERT INTO nested_obj_update VALUES
+  (1, '{"a": [1,2,3], "b": [4,5,6], "c": [7,8,9], "d": [1,2,1,2]}', '4'),
+  (2, '{"a": [10,20,30], "b": [41,51,61], "c": [72,82,92], "d": [11,21,11,21]}', '6');
+BEGIN;
+-- Pushdown plan
+UPDATE nested_obj_update
+SET data['a'][0] = (updated_vals.b * 1)::TEXT::JSONB,
+    data['b'][2] = (updated_vals.c * 2)::TEXT::JSONB,
+    data['c'][0] = (updated_vals.d * 3)::TEXT::JSONB,
+    text_col = (nested_obj_update.id*1000)::TEXT,
+    data['a'][0] = (text_col::INT * data['a'][0]::INT)::TEXT::JSONB,
+    data['d'][6] = (nested_obj_update.id*1)::TEXT::JSONB,
+    data['d'][4] = (nested_obj_update.id*2)::TEXT::JSONB
+FROM (
+  SELECT id,
+         data['a'][0] AS a,
+         data['b'][0]::NUMERIC + 1 AS b,
+         data['c'][0]::NUMERIC + 2 AS c,
+         data['c'][1]::NUMERIC + 3 AS d
+  FROM nested_obj_update
+) updated_vals
+WHERE nested_obj_update.id = updated_vals.id;
+SELECT * FROM nested_obj_update ORDER BY 1,2,3;
+ id |                                              data                                              | text_col
+---------------------------------------------------------------------
+  1 | {"a": [4, 2, 3], "b": [4, 5, 18], "c": [33, 8, 9], "d": [1, 2, 1, 2, 2, null, 1]}              | 1000
+  2 | {"a": [60, 20, 30], "b": [41, 51, 148], "c": [255, 82, 92], "d": [11, 21, 11, 21, 4, null, 2]} | 2000
+(2 rows)
+
+ROLLBACK;
+BEGIN;
+-- Router plan
+UPDATE nested_obj_update
+SET data['a'][0] = (updated_vals.b * 1)::TEXT::JSONB,
+    data['b'][2] = (updated_vals.c * 2)::TEXT::JSONB,
+    data['c'][0] = (updated_vals.d * 3)::TEXT::JSONB,
+    text_col = (nested_obj_update.id*1000)::TEXT,
+    data['a'][0] = (text_col::INT * data['a'][0]::INT)::TEXT::JSONB,
+    data['d'][6] = (nested_obj_update.id*1)::TEXT::JSONB,
+    data['d'][4] = (nested_obj_update.id*2)::TEXT::JSONB
+FROM (
+  SELECT id,
+         data['a'][0] AS a,
+         data['b'][0]::NUMERIC + 1 AS b,
+         data['c'][0]::NUMERIC + 2 AS c,
+         data['c'][1]::NUMERIC + 3 AS d
+  FROM nested_obj_update
+) updated_vals
+WHERE nested_obj_update.id = updated_vals.id
+    AND nested_obj_update.id = 2;
+SELECT * FROM nested_obj_update WHERE id = 2 ORDER BY 1,2,3;
+ id |                                              data                                              | text_col
+---------------------------------------------------------------------
+  2 | {"a": [60, 20, 30], "b": [41, 51, 148], "c": [255, 82, 92], "d": [11, 21, 11, 21, 4, null, 2]} | 2000
+(1 row)
+
+ROLLBACK;
+-- suppress cascade messages
+SET client_min_messages to ERROR;
+DROP SCHEMA multi_update_select CASCADE;
+RESET client_min_messages;

src/test/regress/expected/query_single_shard_table.out

@@ -308,9 +308,11 @@ DEBUG:  Local tables cannot be used in distributed queries.
 DEBUG:  Wrapping relation "citus_local_table" "d1" to a subquery
 DEBUG:  Distributed planning for a fast-path router query
 DEBUG:  Creating router plan
+DEBUG:  Fast-path router query: created local execution plan to avoid deparse and compile of shard query
 DEBUG:  generating subplan XXX_1 for subquery SELECT NULL::integer AS "dummy-1" FROM query_single_shard_table.citus_local_table d1 WHERE true
 DEBUG:  Plan XXX query after replacing subqueries and CTEs: SELECT count(*) AS count FROM (SELECT NULL::integer AS a, NULL::integer AS b FROM (SELECT intermediate_result."dummy-1" FROM read_intermediate_result('XXX_1'::text, 'binary'::citus_copy_format) intermediate_result("dummy-1" integer)) d1_1) d1, query_single_shard_table.nullkey_c1_t1
 DEBUG:  Creating router plan
+DEBUG:  Local executor: Using task's cached local plan for task 0
  count
 ---------------------------------------------------------------------
    121
@@ -599,9 +601,11 @@ DEBUG:  Local tables cannot be used in distributed queries.
 DEBUG:  Wrapping relation "citus_local_table" to a subquery
 DEBUG:  Distributed planning for a fast-path router query
 DEBUG:  Creating router plan
+DEBUG:  Fast-path router query: created local execution plan to avoid deparse and compile of shard query
 DEBUG:  generating subplan XXX_1 for subquery SELECT a, b FROM query_single_shard_table.citus_local_table WHERE true
 DEBUG:  Plan XXX query after replacing subqueries and CTEs: SELECT nullkey_c1_t1.a, nullkey_c1_t1.b, citus_local_table.b FROM (query_single_shard_table.nullkey_c1_t1 JOIN (SELECT citus_local_table_1.a, citus_local_table_1.b FROM (SELECT intermediate_result.a, intermediate_result.b FROM read_intermediate_result('XXX_1'::text, 'binary'::citus_copy_format) intermediate_result(a integer, b integer)) citus_local_table_1) citus_local_table USING (a)) ORDER BY nullkey_c1_t1.a, nullkey_c1_t1.b, citus_local_table.b
 DEBUG:  Creating router plan
+DEBUG:  Local executor: Using task's cached local plan for task 0
  a | b | b
 ---------------------------------------------------------------------
  1 | 1 | 1
@@ -850,9 +854,11 @@ DEBUG:  Local tables cannot be used in distributed queries.
 DEBUG:  Wrapping relation "citus_local_table" to a subquery
 DEBUG:  Distributed planning for a fast-path router query
 DEBUG:  Creating router plan
+DEBUG:  Fast-path router query: created local execution plan to avoid deparse and compile of shard query
 DEBUG:  generating subplan XXX_1 for subquery SELECT a FROM query_single_shard_table.citus_local_table WHERE true
 DEBUG:  Plan XXX query after replacing subqueries and CTEs: SELECT count(*) AS count FROM (query_single_shard_table.nullkey_c1_t1 LEFT JOIN (SELECT citus_local_table_1.a, NULL::integer AS b FROM (SELECT intermediate_result.a FROM read_intermediate_result('XXX_1'::text, 'binary'::citus_copy_format) intermediate_result(a integer)) citus_local_table_1) citus_local_table USING (a))
 DEBUG:  Creating router plan
+DEBUG:  Local executor: Using task's cached local plan for task 0
  count
 ---------------------------------------------------------------------
     11
@@ -863,6 +869,7 @@ DEBUG:  Local tables cannot be used in distributed queries.
 DEBUG:  Wrapping relation "citus_local_table" to a subquery
 DEBUG:  Distributed planning for a fast-path router query
 DEBUG:  Creating router plan
+DEBUG:  Fast-path router query: created local execution plan to avoid deparse and compile of shard query
 DEBUG:  generating subplan XXX_1 for subquery SELECT a FROM query_single_shard_table.citus_local_table WHERE true
 DEBUG:  recursively planning right side of the left join since the outer side is a recurring rel
 DEBUG:  recursively planning distributed relation "nullkey_c1_t1" since it is part of a distributed join node that is outer joined with a recurring rel
@@ -872,6 +879,7 @@ DEBUG:  Creating router plan
 DEBUG:  generating subplan XXX_2 for subquery SELECT a FROM query_single_shard_table.nullkey_c1_t1 WHERE true
 DEBUG:  Plan XXX query after replacing subqueries and CTEs: SELECT count(*) AS count FROM ((SELECT citus_local_table_1.a, NULL::integer AS b FROM (SELECT intermediate_result.a FROM read_intermediate_result('XXX_1'::text, 'binary'::citus_copy_format) intermediate_result(a integer)) citus_local_table_1) citus_local_table LEFT JOIN (SELECT nullkey_c1_t1_1.a, NULL::integer AS b FROM (SELECT intermediate_result.a FROM read_intermediate_result('XXX_2'::text, 'binary'::citus_copy_format) intermediate_result(a integer)) nullkey_c1_t1_1) nullkey_c1_t1 USING (a))
 DEBUG:  Creating router plan
+DEBUG:  Local executor: Using task's cached local plan for task 0
  count
 ---------------------------------------------------------------------
     14
@@ -910,6 +918,7 @@ DEBUG:  Local tables cannot be used in distributed queries.
 DEBUG:  Wrapping relation "citus_local_table" to a subquery
 DEBUG:  Distributed planning for a fast-path router query
 DEBUG:  Creating router plan
+DEBUG:  Fast-path router query: created local execution plan to avoid deparse and compile of shard query
 DEBUG:  generating subplan XXX_1 for subquery SELECT a FROM query_single_shard_table.citus_local_table WHERE true
 DEBUG:  recursively planning left side of the full join since the other side is a recurring rel
 DEBUG:  recursively planning distributed relation "nullkey_c1_t1" since it is part of a distributed join node that is outer joined with a recurring rel
@@ -919,6 +928,7 @@ DEBUG:  Creating router plan
 DEBUG:  generating subplan XXX_2 for subquery SELECT a FROM query_single_shard_table.nullkey_c1_t1 WHERE true
 DEBUG:  Plan XXX query after replacing subqueries and CTEs: SELECT count(*) AS count FROM ((SELECT nullkey_c1_t1_1.a, NULL::integer AS b FROM (SELECT intermediate_result.a FROM read_intermediate_result('XXX_2'::text, 'binary'::citus_copy_format) intermediate_result(a integer)) nullkey_c1_t1_1) nullkey_c1_t1 FULL JOIN (SELECT citus_local_table_1.a, NULL::integer AS b FROM (SELECT intermediate_result.a FROM read_intermediate_result('XXX_1'::text, 'binary'::citus_copy_format) intermediate_result(a integer)) citus_local_table_1) citus_local_table USING (a))
 DEBUG:  Creating router plan
+DEBUG:  Local executor: Using task's cached local plan for task 0
  count
 ---------------------------------------------------------------------
     14
@@ -1222,12 +1232,14 @@ DEBUG:  Local tables cannot be used in distributed queries.
 DEBUG:  Wrapping relation "citus_local_table" "t1" to a subquery
 DEBUG:  Distributed planning for a fast-path router query
 DEBUG:  Creating router plan
+DEBUG:  Fast-path router query: created local execution plan to avoid deparse and compile of shard query
 DEBUG:  generating subplan XXX_1 for subquery SELECT a FROM query_single_shard_table.citus_local_table t1 WHERE true
 DEBUG:  recursively planning right side of the left join since the outer side is a recurring rel
 DEBUG:  recursively planning the distributed subquery since it is part of a distributed join node that is outer joined with a recurring rel
 DEBUG:  skipping recursive planning for the subquery since it contains references to outer queries
 DEBUG:  Plan XXX query after replacing subqueries and CTEs: SELECT count(*) AS count FROM ((SELECT t1_1.a, NULL::integer AS b FROM (SELECT intermediate_result.a FROM read_intermediate_result('XXX_1'::text, 'binary'::citus_copy_format) intermediate_result(a integer)) t1_1) t1 LEFT JOIN LATERAL (SELECT t2.a, t2.b FROM query_single_shard_table.nullkey_c1_t1 t2 WHERE (t2.b OPERATOR(pg_catalog.>) t1.a)) q USING (a))
 DEBUG:  Creating router plan
+DEBUG:  Local executor: Using task's cached local plan for task 0
  count
 ---------------------------------------------------------------------
     11
@@ -1279,9 +1291,11 @@ DEBUG:  Local tables cannot be used in distributed queries.
 DEBUG:  Wrapping relation "citus_local_table" "t1" to a subquery
 DEBUG:  Distributed planning for a fast-path router query
 DEBUG:  Creating router plan
+DEBUG:  Fast-path router query: created local execution plan to avoid deparse and compile of shard query
 DEBUG:  generating subplan XXX_1 for subquery SELECT a FROM query_single_shard_table.citus_local_table t1 WHERE true
 DEBUG:  Plan XXX query after replacing subqueries and CTEs: SELECT count(*) AS count FROM ((SELECT t1_1.a, NULL::integer AS b FROM (SELECT intermediate_result.a FROM read_intermediate_result('XXX_1'::text, 'binary'::citus_copy_format) intermediate_result(a integer)) t1_1) t1 JOIN LATERAL (SELECT t2.a, t2.b FROM query_single_shard_table.nullkey_c1_t1 t2 WHERE (t2.b OPERATOR(pg_catalog.>) t1.a)) q USING (a))
 DEBUG:  Creating router plan
+DEBUG:  Local executor: Using task's cached local plan for task 0
  count
 ---------------------------------------------------------------------
      2
@@ -1428,7 +1442,9 @@ DEBUG:  Creating router plan
 DEBUG:  distributed INSERT ... SELECT cannot select from a local relation when inserting into a distributed table
 DEBUG:  Distributed planning for a fast-path router query
 DEBUG:  Creating router plan
+DEBUG:  Fast-path router query: created local execution plan to avoid deparse and compile of shard query
 DEBUG:  Collecting INSERT ... SELECT results on coordinator
+DEBUG:  Local executor: Using task's cached local plan for task 0
 INSERT INTO nullkey_c1_t1 SELECT * FROM postgres_local_table;
 DEBUG:  Creating router plan
 DEBUG:  distributed INSERT ... SELECT can only select from distributed tables
@@ -2112,9 +2128,11 @@ DEBUG:  local table citus_local_table cannot be joined with these distributed ta
 DEBUG:  Wrapping relation "citus_local_table" to a subquery
 DEBUG:  Distributed planning for a fast-path router query
 DEBUG:  Creating router plan
+DEBUG:  Fast-path router query: created local execution plan to avoid deparse and compile of shard query
 DEBUG:  generating subplan XXX_1 for subquery SELECT b FROM query_single_shard_table.citus_local_table WHERE true
 DEBUG:  Plan XXX query after replacing subqueries and CTEs: UPDATE query_single_shard_table.nullkey_c1_t1 SET b = 5 FROM (SELECT NULL::integer AS a, citus_local_table_1.b FROM (SELECT intermediate_result.b FROM read_intermediate_result('XXX_1'::text, 'binary'::citus_copy_format) intermediate_result(b integer)) citus_local_table_1) citus_local_table WHERE (nullkey_c1_t1.b OPERATOR(pg_catalog.=) citus_local_table.b)
 DEBUG:  Creating router plan
+DEBUG:  Local executor: Using task's cached local plan for task 0
 UPDATE nullkey_c1_t1 SET b = 5 FROM postgres_local_table WHERE nullkey_c1_t1.b = postgres_local_table.b;
 DEBUG:  relation postgres_local_table is not distributed
 DEBUG:  Wrapping relation "postgres_local_table" to a subquery
@@ -2164,9 +2182,11 @@ DEBUG:  local table citus_local_table cannot be joined with these distributed ta
 DEBUG:  Wrapping relation "citus_local_table" to a subquery
 DEBUG:  Distributed planning for a fast-path router query
 DEBUG:  Creating router plan
+DEBUG:  Fast-path router query: created local execution plan to avoid deparse and compile of shard query
 DEBUG:  generating subplan XXX_1 for subquery SELECT b FROM query_single_shard_table.citus_local_table WHERE true
 DEBUG:  Plan XXX query after replacing subqueries and CTEs: DELETE FROM query_single_shard_table.nullkey_c1_t1 USING (SELECT NULL::integer AS a, citus_local_table_1.b FROM (SELECT intermediate_result.b FROM read_intermediate_result('XXX_1'::text, 'binary'::citus_copy_format) intermediate_result(b integer)) citus_local_table_1) citus_local_table WHERE (nullkey_c1_t1.b OPERATOR(pg_catalog.=) citus_local_table.b)
 DEBUG:  Creating router plan
+DEBUG:  Local executor: Using task's cached local plan for task 0
 DELETE FROM nullkey_c1_t1 USING postgres_local_table WHERE nullkey_c1_t1.b = postgres_local_table.b;
 DEBUG:  relation postgres_local_table is not distributed
 DEBUG:  Wrapping relation "postgres_local_table" to a subquery

src/test/regress/expected/stat_counters.out

@@ -721,13 +721,11 @@ CALL exec_query_and_check_query_counters($$
     0, 0
 );
 -- same with explain analyze
---
--- this time, query_execution_multi_shard is incremented twice because of #4212
 CALL exec_query_and_check_query_counters($$
     EXPLAIN (ANALYZE)
     SELECT * FROM (SELECT * FROM dist_table OFFSET 0) q
     $$,
-    1, 2
+    1, 1
 );
 CALL exec_query_and_check_query_counters($$
     DELETE FROM dist_table WHERE a = 1
@@ -1041,9 +1039,6 @@ PL/pgSQL function exec_query_and_check_query_counters(text,bigint,bigint) line X
 -- A similar one but without the insert, so we would normally expect 2 increments
 -- for query_execution_single_shard and 2 for query_execution_multi_shard instead
 -- of 3 since the insert is not there anymore.
---
--- But this time we observe more counter increments because we execute the subplans
--- twice because of #4212.
 CALL exec_query_and_check_query_counters($$
     EXPLAIN (ANALYZE)
     -- single-shard subplan (whole cte)
@@ -1057,7 +1052,7 @@ CALL exec_query_and_check_query_counters($$
     FROM (SELECT * FROM dist_table_1 ORDER BY a LIMIT 16) q -- multi-shard subplan (subquery q)
     JOIN cte ON q.a = cte.a
     $$,
-    3, 4
+    2, 2
 );
 -- safe to push-down
 CALL exec_query_and_check_query_counters($$

src/test/regress/expected/subscripting_op.out

@@ -0,0 +1,105 @@
+\set VERBOSITY terse
+SET citus.next_shard_id TO 1520000;
+CREATE SCHEMA subscripting_op;
+SET search_path TO subscripting_op;
+CREATE TABLE arr_subs_update(id INT, arr INT[], text_col TEXT, int_col_1 INT, int_col_2 INT);
+SELECT create_distributed_table('arr_subs_update', 'id');
+ create_distributed_table
+---------------------------------------------------------------------
+
+(1 row)
+
+INSERT INTO arr_subs_update
+  VALUES (1, '{1,2,3}', 'foo', 50, 60),
+         (2, '{4,5,6}', 'bar', 60, 70),
+         (3, '{7,8,9}', 'baz', 70, 80);
+BEGIN;
+UPDATE arr_subs_update
+SET arr[1] = updated_vals.b,
+    arr[3] = updated_vals.d,
+    int_col_2 = 400,
+    arr[2] = updated_vals.c
+FROM (
+  SELECT id,
+         arr[0] AS a,
+         arr[1]::NUMERIC + 1 AS b,
+         arr[2]::NUMERIC + 2 AS c,
+         arr[3]::NUMERIC + 3 AS d
+  FROM arr_subs_update
+) updated_vals
+WHERE arr_subs_update.id = updated_vals.id;
+SELECT * FROM arr_subs_update ORDER BY 1,2,3,4;
+ id |    arr    | text_col | int_col_1 | int_col_2
+---------------------------------------------------------------------
+  1 | {2,4,6}   | foo      |        50 |       400
+  2 | {5,7,9}   | bar      |        60 |       400
+  3 | {8,10,12} | baz      |        70 |       400
+(3 rows)
+
+ROLLBACK;
+BEGIN;
+-- Test fast path router plan for subscripting update
+UPDATE arr_subs_update
+SET arr[1] = updated_vals.b,
+    arr[3] = updated_vals.d,
+    int_col_2 = 400,
+    arr[2] = updated_vals.c
+FROM (
+  SELECT id,
+         arr[0] AS a,
+         arr[1]::NUMERIC + 1 AS b,
+         arr[2]::NUMERIC + 2 AS c,
+         arr[3]::NUMERIC + 3 AS d
+  FROM arr_subs_update
+) updated_vals
+WHERE arr_subs_update.id = updated_vals.id
+  AND arr_subs_update.id = 1;
+SELECT * FROM arr_subs_update
+WHERE id=1 ORDER BY 1,2,3,4;
+ id |   arr   | text_col | int_col_1 | int_col_2
+---------------------------------------------------------------------
+  1 | {2,4,6} | foo      |        50 |       400
+(1 row)
+
+ROLLBACK;
+-- test if we can properly expand target list entries when there are dropped columns
+ALTER TABLE arr_subs_update DROP COLUMN int_col_1;
+BEGIN;
+UPDATE arr_subs_update
+SET arr[1] = updated_vals.b,
+    arr[3] = updated_vals.d,
+    int_col_2 = 400,
+    arr[2] = updated_vals.c
+FROM (
+  SELECT id,
+         arr[0] AS a,
+         arr[1]::NUMERIC + 1 AS b,
+         arr[2]::NUMERIC + 2 AS c,
+         arr[3]::NUMERIC + 3 AS d
+  FROM arr_subs_update
+) updated_vals
+WHERE arr_subs_update.id = updated_vals.id;
+SELECT * FROM arr_subs_update ORDER BY 1,2,3,4;
+ id |    arr    | text_col | int_col_2
+---------------------------------------------------------------------
+  1 | {2,4,6}   | foo      |       400
+  2 | {5,7,9}   | bar      |       400
+  3 | {8,10,12} | baz      |       400
+(3 rows)
+
+ROLLBACK;
+TRUNCATE arr_subs_update;
+INSERT INTO arr_subs_update VALUES (1, '{1,2,3}', 'foo', 60), (2, '{4,5,6}', 'bar', 70);
+ALTER TABLE arr_subs_update ADD CONSTRAINT pkey PRIMARY KEY (id, arr);
+INSERT INTO arr_subs_update VALUES (1, '{1,2,3}')
+ON CONFLICT (id, arr)
+DO UPDATE SET arr[0]=100, arr[1]=200, arr[5]=500;
+SELECT * FROM arr_subs_update ORDER BY 1,2,3,4;
+ id |             arr              | text_col | int_col_2
+---------------------------------------------------------------------
+  1 | [0:5]={100,200,2,3,NULL,500} | foo      |        60
+  2 | {4,5,6}                      | bar      |        70
+(2 rows)
+
+SET client_min_messages TO WARNING;
+DROP SCHEMA subscripting_op CASCADE;

src/test/regress/expected/union_pushdown.out

@@ -1469,5 +1469,140 @@ $$);
  f
 (1 row)
 
+CREATE TABLE dist1 (a int, b int);
+CREATE TABLE dist2 (a int, b int);
+SET citus.shard_count to 4;
+SELECT create_distributed_table('dist1', 'a');
+ create_distributed_table
+---------------------------------------------------------------------
+
+(1 row)
+
+SELECT create_distributed_table('dist2', 'a');
+ create_distributed_table
+---------------------------------------------------------------------
+
+(1 row)
+
+INSERT INTO dist1 VALUES (1, 1), (2, 1), (3, 1), (4, 1), (5, 1);
+INSERT INTO dist2 VALUES (5, 2), (6, 2), (7, 2), (8, 2), (9, 2);
+-- safe to pushdown
+SELECT * FROM
+(
+  SELECT * FROM dist1 JOIN dist2 USING (a)
+  UNION
+  SELECT * FROM dist1 JOIN dist2 USING (a)
+) AS t1 ORDER BY 1;
+ a | b | b
+---------------------------------------------------------------------
+ 5 | 1 | 2
+(1 row)
+
+-- not safe to pushdown, the distribution key from the outer part of the outer join is not in the target list
+SELECT * FROM
+(
+  SELECT dist2.a FROM dist1 LEFT JOIN dist2 USING (a)
+  UNION
+  SELECT dist2.a FROM dist2
+) AS t1 ORDER BY 1;
+ a
+---------------------------------------------------------------------
+ 5
+ 6
+ 7
+ 8
+ 9
+
+(6 rows)
+
+set client_min_messages to DEBUG3;
+-- not safe to pushdown, as is, sub-plan is generated
+-- the distribution key from the outer part of the outer join is not in the target list
+SELECT * FROM
+(
+  SELECT dist1.a FROM dist1 RIGHT JOIN dist2 USING (a)
+  UNION
+  SELECT dist2.a FROM dist2
+) AS t1 ORDER BY 1;
+DEBUG:  no shard pruning constraints on dist1 found
+DEBUG:  shard count after pruning for dist1: 4
+DEBUG:  no shard pruning constraints on dist2 found
+DEBUG:  shard count after pruning for dist2: 4
+DEBUG:  no shard pruning constraints on dist2 found
+DEBUG:  shard count after pruning for dist2: 4
+DEBUG:  Router planner cannot handle multi-shard select queries
+DEBUG:  no shard pruning constraints on dist1 found
+DEBUG:  shard count after pruning for dist1: 4
+DEBUG:  no shard pruning constraints on dist2 found
+DEBUG:  shard count after pruning for dist2: 4
+DEBUG:  Router planner cannot handle multi-shard select queries
+DEBUG:  no shard pruning constraints on dist1 found
+DEBUG:  shard count after pruning for dist1: 4
+DEBUG:  no shard pruning constraints on dist2 found
+DEBUG:  shard count after pruning for dist2: 4
+DEBUG:  assigned task to node localhost:xxxxx
+DEBUG:  assigned task to node localhost:xxxxx
+DEBUG:  assigned task to node localhost:xxxxx
+DEBUG:  assigned task to node localhost:xxxxx
+DEBUG:  generating subplan XXX_1 for subquery SELECT dist1.a FROM (union_pushdown.dist1 RIGHT JOIN union_pushdown.dist2 USING (a))
+DEBUG:  no shard pruning constraints on dist2 found
+DEBUG:  shard count after pruning for dist2: 4
+DEBUG:  Router planner cannot handle multi-shard select queries
+DEBUG:  no shard pruning constraints on dist2 found
+DEBUG:  shard count after pruning for dist2: 4
+DEBUG:  assigned task to node localhost:xxxxx
+DEBUG:  assigned task to node localhost:xxxxx
+DEBUG:  assigned task to node localhost:xxxxx
+DEBUG:  assigned task to node localhost:xxxxx
+DEBUG:  generating subplan XXX_2 for subquery SELECT a FROM union_pushdown.dist2
+DEBUG:  Creating router plan
+DEBUG:  generating subplan XXX_3 for subquery SELECT intermediate_result.a FROM read_intermediate_result('XXX_1'::text, 'binary'::citus_copy_format) intermediate_result(a integer) UNION SELECT intermediate_result.a FROM read_intermediate_result('XXX_2'::text, 'binary'::citus_copy_format) intermediate_result(a integer)
+DEBUG:  Plan XXX query after replacing subqueries and CTEs: SELECT a FROM (SELECT intermediate_result.a FROM read_intermediate_result('XXX_3'::text, 'binary'::citus_copy_format) intermediate_result(a integer)) t1 ORDER BY a
+DEBUG:  Creating router plan
+ a
+---------------------------------------------------------------------
+ 5
+ 6
+ 7
+ 8
+ 9
+
+(6 rows)
+
+-- safe to pushdown, the distribution key from the outer side of the RIGHT join is in the target list
+SELECT * FROM
+(
+  SELECT dist2.a
+    FROM dist1 RIGHT JOIN dist2 USING (a)
+  UNION
+  SELECT dist2.a FROM dist2
+) AS t1
+ORDER BY 1;
+DEBUG:  no shard pruning constraints on dist1 found
+DEBUG:  shard count after pruning for dist1: 4
+DEBUG:  no shard pruning constraints on dist2 found
+DEBUG:  shard count after pruning for dist2: 4
+DEBUG:  no shard pruning constraints on dist2 found
+DEBUG:  shard count after pruning for dist2: 4
+DEBUG:  Router planner cannot handle multi-shard select queries
+DEBUG:  no shard pruning constraints on dist1 found
+DEBUG:  shard count after pruning for dist1: 4
+DEBUG:  no shard pruning constraints on dist2 found
+DEBUG:  shard count after pruning for dist2: 4
+DEBUG:  no shard pruning constraints on dist2 found
+DEBUG:  shard count after pruning for dist2: 4
+DEBUG:  assigned task to node localhost:xxxxx
+DEBUG:  assigned task to node localhost:xxxxx
+DEBUG:  assigned task to node localhost:xxxxx
+DEBUG:  assigned task to node localhost:xxxxx
+ a
+---------------------------------------------------------------------
+ 5
+ 6
+ 7
+ 8
+ 9
+(5 rows)
+
 SET client_min_messages TO WARNING;
 DROP SCHEMA union_pushdown CASCADE;

src/test/regress/multi_1_schedule

@@ -210,6 +210,7 @@ test: multi_outer_join
 # ---
 test: multi_complex_count_distinct multi_select_distinct
 test: multi_modifications
+test: multi_update_select
 test: multi_distribution_metadata
 test: multi_prune_shard_list
 test: multi_upsert multi_simple_queries multi_data_types

src/test/regress/multi_mx_schedule

@@ -70,6 +70,7 @@ test: metadata_sync_helpers
 
 test: issue_6592
 test: executor_local_failure
+test: local_execution_local_plan
 
 # test that no tests leaked intermediate results. This should always be last
 test: ensure_no_intermediate_data_leak

src/test/regress/multi_schedule

@@ -93,6 +93,7 @@ test: multi_average_expression multi_working_columns multi_having_pushdown havin
 test: multi_array_agg multi_limit_clause multi_orderby_limit_pushdown
 test: multi_jsonb_agg multi_jsonb_object_agg multi_json_agg multi_json_object_agg bool_agg ch_bench_having chbenchmark_all_queries expression_reference_join anonymous_columns
 test: ch_bench_subquery_repartition
+test: subscripting_op
 test: multi_agg_type_conversion multi_count_type_conversion recursive_relation_planning_restriction_pushdown
 test: multi_partition_pruning single_hash_repartition_join unsupported_lateral_subqueries
 test: multi_join_pruning multi_hash_pruning intermediate_result_pruning

src/test/regress/sql/local_execution_local_plan.sql

@@ -0,0 +1,214 @@
+-- Test local execution with local plan in a sharded environment.
+-- This is an enhancement to local execution where instead of deparsing
+-- and compiling the shard query, the planner replaces the OID of the
+-- distributed table with the OID of the local shard in the parse tree
+-- and plans that.
+--
+-- https://github.com/citusdata/citus/pull/8035
+
+CREATE SCHEMA local_shard_execution_local_plan;
+SET search_path TO local_shard_execution_local_plan;
+
+SET citus.next_shard_id TO 86000000;
+
+-- Test row-based sharding
+
+SET citus.shard_replication_factor TO 1;
+CREATE TABLE test_tbl (a int, b int, data_f double precision);
+SELECT create_distributed_table('test_tbl', 'a');
+SELECT setseed(0.42); -- make the random data inserted deterministic
+INSERT INTO test_tbl
+SELECT (random()*20)::int AS a,
+       (random()*20)::int AS b,
+       random()*10000.0 AS data_f
+FROM generate_series(1, 10000);
+
+-- Put the shard on worker 1 to ensure consistent test output across different schedules
+SET client_min_messages to ERROR; -- suppress warning if shard is already on worker 1
+SELECT citus_move_shard_placement(86000000, 'localhost', :worker_2_port, 'localhost', :worker_1_port, 'block_writes');
+SELECT public.wait_for_resource_cleanup(); -- otherwise fails flakiness tests
+RESET client_min_messages;
+
+\c - - - :worker_1_port
+SET search_path TO local_shard_execution_local_plan;
+
+SET client_min_messages TO DEBUG2;
+SET citus.log_remote_commands TO ON;
+SET citus.log_local_commands TO ON;
+
+-- This query resolves to a single shard (aka fast path)
+-- which is located on worker_1; with client_min_messages
+-- at DEBUG2 we see a message that the planner is avoiding
+-- query deparse and plan
+SELECT b, AVG(data_f), MIN(data_f), MAX(data_f), COUNT(1)
+FROM test_tbl
+WHERE a = 8 AND b IN (1,3,5,8,13,21)
+GROUP BY b
+ORDER BY b;
+
+BEGIN;
+  -- force accessing local placements via remote connections first
+  SET citus.enable_local_execution TO false;
+  RESET client_min_messages;
+  RESET citus.log_remote_commands;
+  RESET citus.log_local_commands;
+  SELECT count(*), b FROM test_tbl GROUP BY b ORDER BY b;
+  -- Now, even if we enable local execution back before the query that
+  -- could normally benefit from fast path local query optimizations,
+  -- this time it won't be the case because local execution was implicitly
+  -- disabled by Citus as we accessed local shard placements via remote
+  -- connections.
+  SET citus.enable_local_execution TO true;
+  SET client_min_messages TO DEBUG2;
+  SET citus.log_remote_commands TO ON;
+  SET citus.log_local_commands TO ON;
+  SELECT b, AVG(data_f), MIN(data_f), MAX(data_f), COUNT(1)
+  FROM test_tbl
+  WHERE a = 8 AND b IN (1,3,5,8,13,21)
+  GROUP BY b
+  ORDER BY b;
+SET client_min_messages TO ERROR; -- keep COMMIT output quiet
+COMMIT;
+SET client_min_messages TO DEBUG2;
+
+SET citus.enable_local_fast_path_query_optimization TO OFF;
+
+-- With local execution local plan disabled, the same query
+-- does query deparse and planning of the shard query and
+-- provides the same results
+SELECT b, AVG(data_f), MIN(data_f), MAX(data_f), COUNT(1)
+FROM test_tbl
+WHERE a = 8 AND b IN (1,3,5,8,13,21)
+GROUP BY b
+ORDER BY b;
+
+\c - - - :worker_2_port
+SET search_path TO local_shard_execution_local_plan;
+
+SET client_min_messages TO DEBUG2;
+SET citus.log_remote_commands TO ON;
+SET citus.log_local_commands TO ON;
+
+-- Run the same query on the other worker - the local
+-- execution path is not taken because the shard is not
+-- local to this worker
+SELECT b, AVG(data_f), MIN(data_f), MAX(data_f), COUNT(1)
+FROM test_tbl
+WHERE a = 8 AND b IN (1,3,5,8,13,21)
+GROUP BY b
+ORDER BY b;
+
+\c - - - :master_port
+
+SET search_path TO local_shard_execution_local_plan;
+SET citus.next_shard_id TO 86001000;
+
+-- Test citus local and reference tables
+CREATE TABLE ref_tbl (a int, b int, data_f double precision);
+SELECT create_reference_table('ref_tbl');
+SELECT setseed(0.42); -- make the random data inserted deterministic
+INSERT INTO ref_tbl
+SELECT (random()*20)::int AS a,
+       (random()*20)::int AS b,
+       random()*10000.0 AS data_f
+FROM generate_series(1, 10000);
+
+SET citus.next_shard_id TO 86002000;
+CREATE TABLE citus_tbl (a int, b int, data_f double precision);
+SELECT citus_set_coordinator_host('localhost', :master_port);
+SELECT citus_add_local_table_to_metadata('citus_tbl');
+INSERT INTO citus_tbl SELECT a, b, data_f FROM ref_tbl;
+
+SET client_min_messages TO DEBUG2;
+SET citus.log_remote_commands TO ON;
+SET citus.log_local_commands TO ON;
+
+-- citus local table: can use the fast path optimization
+SELECT b, AVG(data_f), MIN(data_f), MAX(data_f), COUNT(1)
+FROM citus_tbl
+WHERE a = 8 AND b IN (1,3,5,8,13,21)
+GROUP BY b
+ORDER BY b;
+
+-- reference table: does not use the fast path optimization.
+-- It may be enabled in a future enhancement.
+SELECT b, AVG(data_f), MIN(data_f), MAX(data_f), COUNT(1)
+FROM ref_tbl
+WHERE a = 8 AND b IN (1,3,5,8,13,21)
+GROUP BY b
+ORDER BY b;
+
+\c - - - :master_port
+
+-- Now test local execution with local plan for a schema sharded table.
+
+SET citus.enable_schema_based_sharding to on;
+CREATE SCHEMA schema_sharding_test;
+SET search_path TO schema_sharding_test;
+
+SET citus.next_shard_id TO 87000000;
+
+SET citus.shard_replication_factor TO 1;
+CREATE TABLE test_tbl (a int, b int, data_f double precision);
+SELECT setseed(0.42); -- make the random data inserted deterministic
+INSERT INTO test_tbl
+SELECT (random()*20)::int AS a,
+       (random()*20)::int AS b,
+       random()*10000.0 AS data_f
+FROM generate_series(1, 10000);
+
+-- Put the shard on worker 2 to ensure consistent test output across different schedules
+SET client_min_messages to ERROR; -- suppress warning if shard is already on worker 2
+SELECT citus_move_shard_placement(87000000, 'localhost', :worker_1_port, 'localhost', :worker_2_port, 'block_writes');
+SELECT public.wait_for_resource_cleanup(); -- otherwise fails flakiness tests
+RESET client_min_messages;
+
+\c - - - :worker_1_port
+
+SET client_min_messages TO DEBUG2;
+SET citus.log_remote_commands TO ON;
+SET citus.log_local_commands TO ON;
+
+-- Run the test query on worker_1; with schema based sharding
+-- the data is not local to this worker so local execution
+-- path is not taken.
+SELECT b, AVG(data_f), MIN(data_f), MAX(data_f), COUNT(1)
+FROM schema_sharding_test.test_tbl
+WHERE a = 8 AND b IN (1,3,5,8,13,21)
+GROUP BY b
+ORDER BY b;
+
+\c - - - :worker_2_port
+
+SET client_min_messages TO DEBUG2;
+SET citus.log_remote_commands TO ON;
+SET citus.log_local_commands TO ON;
+
+-- Run the test query on worker_2; with schema based sharding
+-- the data is local to this worker so local execution
+-- path is taken, and the planner avoids query deparse and
+-- planning of the shard query.
+
+SELECT b, AVG(data_f), MIN(data_f), MAX(data_f), COUNT(1)
+FROM schema_sharding_test.test_tbl
+WHERE a = 8 AND b IN (1,3,5,8,13,21)
+GROUP BY b
+ORDER BY b;
+
+SET citus.enable_local_fast_path_query_optimization TO OFF;
+
+-- Run the test query on worker_2 but with local execution
+-- local plan disabled; now the planner does query deparse
+-- and planning of the shard query.
+SELECT b, AVG(data_f), MIN(data_f), MAX(data_f), COUNT(1)
+FROM schema_sharding_test.test_tbl
+WHERE a = 8 AND b IN (1,3,5,8,13,21)
+GROUP BY b
+ORDER BY b;
+
+\c - - - :master_port
+
+SET client_min_messages to ERROR;
+DROP SCHEMA local_shard_execution_local_plan CASCADE;
+DROP SCHEMA schema_sharding_test CASCADE;
+RESET ALL;

src/test/regress/sql/local_shard_execution_dropped_column.sql

@@ -78,14 +78,37 @@ execute p4(8);
 execute p4(8);
 execute p4(8);
 
+-- Test that "Avoid deparse and planning of shard query for local execution" (*)
+-- does not take the fast path of modifying the parse tree with the shard OID, as
+-- the dropped column means the attribute check between the distributed table and
+-- shard fails. With client_min_messages at DEBUG2, we see "cannot modify parse tree
+-- for local execution", indicating that router planning has detected the difference.
+--
+-- (*) https://github.com/citusdata/citus/pull/8035
+
+SET client_min_messages to DEBUG2;
+prepare p5(int) as SELECT count(*) FROM t1 WHERE c = 8 and a = $1 GROUP BY c;
+execute p5(5);
+execute p5(5);
+execute p5(5);
+execute p5(5);
+execute p5(5);
+execute p5(5);
+execute p5(5);
+execute p5(5);
+execute p5(5);
+execute p5(5);
+RESET client_min_messages;
+
 \c - - - :master_port
 
--- one another combination is that the shell table
+-- one other combination is that the shell table
 -- has a dropped column but not the shard, via rebalance operation
 SET search_path TO local_shard_execution_dropped_column;
 ALTER TABLE t1 DROP COLUMN a;
 
 SELECT citus_move_shard_placement(2460000, 'localhost', :worker_1_port, 'localhost', :worker_2_port, 'block_writes');
+SELECT public.wait_for_resource_cleanup(); -- otherwise fails flakiness tests
 
 \c - - - :worker_2_port
 SET search_path TO local_shard_execution_dropped_column;
@@ -132,5 +155,25 @@ execute p3(8);
 execute p3(8);
 execute p3(8);
 
+-- Test that "Avoid deparse and planning of shard query for local execution"
+-- does not take the fast path of modifying the parse tree with the shard OID
+-- for this scenario (rebalance) also.
+--
+-- (*) https://github.com/citusdata/citus/pull/8035
+
+SET client_min_messages to DEBUG2;
+prepare p4(int) as SELECT count(*) FROM t1 WHERE c = 8 and 5 = $1 GROUP BY c;
+execute p4(5);
+execute p4(5);
+execute p4(5);
+execute p4(5);
+execute p4(5);
+execute p4(5);
+execute p4(5);
+execute p4(5);
+execute p4(5);
+execute p4(5);
+RESET client_min_messages;
+
 \c - - - :master_port
 DROP SCHEMA local_shard_execution_dropped_column CASCADE;

src/test/regress/sql/multi_explain.sql

@@ -1166,6 +1166,32 @@ PREPARE q2(int_wrapper_type) AS WITH a AS (UPDATE tbl SET b = $1 WHERE a = 1 RET
 EXPLAIN (COSTS false) EXECUTE q2('(1)');
 EXPLAIN :default_analyze_flags EXECUTE q2('(1)');
 
+-- EXPLAIN ANALYZE shouldn't execute SubPlans twice (bug #4212)
+SET search_path TO multi_explain;
+CREATE TABLE test_subplans (x int primary key, y int);
+SELECT create_distributed_table('test_subplans','x');
+
+EXPLAIN (COSTS off, ANALYZE on, TIMING off, SUMMARY off)
+WITH a AS (INSERT INTO test_subplans VALUES (1,2) RETURNING *)
+SELECT * FROM a;
+
+-- Only one row must exist
+SELECT * FROM test_subplans;
+
+-- Will fail with duplicate pk
+EXPLAIN (COSTS off, ANALYZE on, TIMING off, SUMMARY off)
+WITH a AS (INSERT INTO test_subplans VALUES (1,2) RETURNING *)
+SELECT * FROM a;
+
+-- Test JSON format
+TRUNCATE test_subplans;
+EXPLAIN (FORMAT JSON, COSTS off, ANALYZE on, TIMING off, SUMMARY off)
+WITH a AS (INSERT INTO test_subplans VALUES (1,2) RETURNING *)
+SELECT * FROM a;
+
+-- Only one row must exist
+SELECT * FROM test_subplans;
+
 -- check when auto explain + analyze is enabled, we do not allow local execution.
 CREATE SCHEMA test_auto_explain;
 SET search_path TO 'test_auto_explain';

src/test/regress/sql/multi_modifications.sql

@@ -234,6 +234,7 @@ SELECT kind, limit_price FROM limit_orders WHERE id = 246;
 
 -- multi-column UPDATE with RETURNING
 UPDATE limit_orders SET (kind, limit_price) = ('buy', 999) WHERE id = 246 RETURNING *;
+UPDATE limit_orders SET (kind, limit_price) = (SELECT 'buy'::order_side, 999) WHERE id = 246 RETURNING *;
 
 -- Test that on unique contraint violations, we fail fast
 \set VERBOSITY terse
@@ -337,6 +338,9 @@ UPDATE limit_orders SET limit_price = 0.00 FROM bidders
 WITH deleted_orders AS (INSERT INTO limit_orders VALUES (399, 'PDR', 14, '2017-07-02 16:32:15', 'sell', 43))
 UPDATE limit_orders SET symbol = 'GM';
 
+WITH deleted_orders AS (INSERT INTO limit_orders SELECT 400, 'PDR', 14, '2017-07-02 16:32:15', 'sell', 43)
+UPDATE limit_orders SET symbol = 'GM';
+
 SELECT symbol, bidder_id FROM limit_orders WHERE id = 246;
 
 -- updates referencing just a var are supported
@@ -584,6 +588,13 @@ WHERE id = 2;
 
 SELECT * FROM summary_table ORDER BY id;
 
+-- try different order of update targets
+UPDATE summary_table SET (average_value, min_value) =
+ 	(SELECT avg(value), min(value) FROM raw_table WHERE id = 2)
+WHERE id = 2;
+
+SELECT * FROM summary_table ORDER BY id;
+
 UPDATE summary_table SET min_value = 100
 	WHERE id IN (SELECT id FROM raw_table WHERE id = 1 and value > 100) AND id = 1;
 
@@ -712,6 +723,12 @@ WHERE id = 2;
 
 SELECT * FROM reference_summary_table ORDER BY id;
 
+UPDATE reference_summary_table SET (average_value, min_value) =
+	(SELECT avg(value), min(value) FROM reference_raw_table WHERE id = 2)
+WHERE id = 2;
+
+SELECT * FROM reference_summary_table ORDER BY id;
+
 -- no need partition colum equalities on reference tables
 UPDATE reference_summary_table SET (count) =
 	(SELECT id AS inner_id FROM reference_raw_table WHERE value = 500)
@@ -902,4 +919,15 @@ DROP TABLE raw_table;
 DROP TABLE summary_table;
 DROP TABLE reference_raw_table;
 DROP TABLE reference_summary_table;
+DROP TABLE limit_orders;
+DROP TABLE multiple_hash;
+DROP TABLE range_partitioned;
+DROP TABLE append_partitioned;
+DROP TABLE bidders;
+
+DROP FUNCTION stable_append;
+DROP FUNCTION immutable_append;
+DROP FUNCTION temp_strict_func;
+DROP TYPE order_side;
+
 DROP SCHEMA multi_modifications CASCADE;

src/test/regress/sql/multi_subquery_in_where_clause.sql

@@ -1,7 +1,7 @@
 --
 -- multi subquery in where queries aims to expand existing subquery pushdown
 -- regression tests to cover more cases specifically subqueries in WHERE clause
--- the tables that are used depends to multi_insert_select_behavioral_analytics_create_table.sql
+-- the tables that are used depends to multi_behavioral_analytics_create_table.sql
 --
 -- We don't need shard id sequence here, so commented out to prevent conflicts with concurrent tests
 

src/test/regress/sql/multi_subquery_misc.sql

@@ -3,7 +3,7 @@
 --   (ii)  PL/PGSQL functions
 --   (iii) SQL functions
 
--- the tables that are used depends to multi_insert_select_behavioral_analytics_create_table.sql
+-- the tables that are used depends to multi_behavioral_analytics_create_table.sql
 
 -- We don't need shard id sequence here, so commented out to prevent conflicts with concurrent tests
 SET citus.enable_router_execution TO false;
@@ -213,6 +213,7 @@ ORDER BY 2 DESC;
 -- Similar to the above queries, but
 -- this time the joins are not removed because
 -- target list contains all the entries
+SET citus.enable_router_execution TO true;
 SELECT
     *
 FROM users_table t1

src/test/regress/sql/multi_subquery_union.sql

@@ -1,7 +1,7 @@
 --
 -- multi subquery toplevel union queries aims to expand existing subquery pushdown
 -- regression tests to cover more cases
--- the tables that are used depends to multi_insert_select_behavioral_analytics_create_table.sql
+-- the tables that are used depends to multi_behavioral_analytics_create_table.sql
 
 -- We don't need shard id sequence here, so commented out to prevent conflicts with concurrent tests
 -- SET citus.next_shard_id TO 1400000;
@@ -898,6 +898,3 @@ LANGUAGE sql stable;
 
 SELECT user_id FROM users_table
 UNION SELECT u.user_id FROM users_table, users_udf() u;
-
-DROP TABLE events_reference_table;
-DROP TABLE users_reference_table;

src/test/regress/sql/multi_update_select.sql

@@ -0,0 +1,416 @@
+CREATE SCHEMA multi_update_select;
+SET search_path TO multi_update_select;
+
+SET citus.next_shard_id TO 751000;
+
+-- specific tests related to get_update_query_targetlist_def
+-- we test only queries with sublinks, like:
+-- ( ... SET (...) = (SELECT ...))
+
+-- Reference tables
+CREATE TABLE test_ref_indirection (
+    id bigint primary key
+  , col_bool bool , col_date date , col_int integer , col_text text
+  );
+SELECT create_reference_table('test_ref_indirection');
+
+CREATE TABLE test_ref_indirection_new (
+    id bigint primary key
+  , col_bool bool , col_date date , col_int integer , col_text text
+  );
+SELECT create_reference_table('test_ref_indirection_new');
+
+-- Distributed tables
+CREATE TABLE test_dist_indirection (
+    id bigint primary key
+  , col_bool bool , col_date date , col_int integer , col_text text
+  );
+SELECT create_distributed_table('test_dist_indirection', 'id');
+
+CREATE TABLE test_dist_indirection_new (
+    id bigint primary key
+  , col_bool bool , col_date date , col_int integer , col_text text
+  );
+SELECT create_distributed_table('test_dist_indirection_new', 'id');
+
+-- those should work:
+INSERT INTO test_ref_indirection (id, col_bool, col_date, col_int, col_text)
+    SELECT 1, true, '1970-01-01'::date, 1, 'one';
+INSERT INTO test_dist_indirection (id, col_bool, col_date, col_int, col_text)
+    SELECT 1, true, '1970-01-01'::date, 1, 'one';
+
+INSERT INTO test_ref_indirection (id, col_text, col_bool, col_date, col_int)
+    SELECT 2, 'two', false, '1970-01-01'::date, 2;
+INSERT INTO test_dist_indirection (id, col_text, col_bool, col_date, col_int)
+    SELECT 2, 'two', false, '1970-01-01'::date, 2;
+
+INSERT INTO test_ref_indirection SELECT 3, false, '1970-01-01'::date, 0, 'empty';
+INSERT INTO test_dist_indirection SELECT 3, false, '1970-01-01'::date, 0, 'empty';
+INSERT INTO test_ref_indirection SELECT 4, false, '1970-01-01'::date, 0, 'empty';
+INSERT INTO test_dist_indirection SELECT 4, false, '1970-01-01'::date, 0, 'empty';
+
+INSERT INTO test_ref_indirection_new SELECT * FROM test_ref_indirection;
+INSERT INTO test_dist_indirection_new SELECT * FROM test_dist_indirection;
+
+SELECT * FROM test_ref_indirection ORDER BY id;
+SELECT * FROM test_dist_indirection ORDER BY id;
+
+SELECT * FROM test_ref_indirection_new ORDER BY id;
+SELECT * FROM test_dist_indirection_new ORDER BY id;
+
+-- now UPDATEs
+UPDATE test_ref_indirection
+    SET (col_bool, col_date, col_int, col_text)
+        = (SELECT true, '1970-01-01'::date, 1, 'ok')
+RETURNING *;
+UPDATE test_dist_indirection
+    SET (col_bool, col_date, col_int, col_text)
+        = (SELECT true, '1970-01-01'::date, 1, 'ok')
+RETURNING *;
+
+UPDATE test_ref_indirection
+    SET (col_bool, col_date)  = (select false, '1971-01-01'::date)
+      , (col_int, col_text) = (select 2, '2 ok')
+RETURNING *;
+UPDATE test_dist_indirection
+    SET (col_bool, col_date)  = (select false, '1971-01-01'::date)
+      , (col_int, col_text) = (select 2, '2 ok')
+RETURNING *;
+
+UPDATE test_ref_indirection
+    SET (col_bool, col_int)  = (select true, 3)
+      , (col_text) = (select '3 ok')
+RETURNING *;
+UPDATE test_dist_indirection
+    SET (col_bool, col_int)  = (select true, 3)
+      , (col_text) = (select '3 ok')
+RETURNING *;
+
+-- but those should work since 13.X
+UPDATE test_ref_indirection
+    SET (col_date, col_text, col_int, col_bool)
+        = (SELECT '1972-01-01'::date, '4 ok', 4, false)
+RETURNING *;
+UPDATE test_dist_indirection
+    SET (col_date, col_text, col_int, col_bool)
+        = (SELECT '1972-01-01'::date, '4 ok', 4, false)
+RETURNING *;
+
+UPDATE test_ref_indirection
+    SET (col_int, col_text)  = (select 5, '5 ok')
+      , (col_bool) = (select true)
+RETURNING *;
+UPDATE test_dist_indirection
+    SET (col_int, col_text)  = (select 5, '5 ok')
+      , (col_bool) = (select true)
+RETURNING *;
+
+UPDATE test_ref_indirection
+    SET (col_int, col_date)  = (select 6, '1973-01-01'::date)
+      , (col_text, col_bool) = (select '6 ok', false)
+RETURNING *;
+UPDATE test_dist_indirection
+    SET (col_int, col_date)  = (select 6, '1973-01-01'::date)
+      , (col_text, col_bool) = (select '6 ok', false)
+RETURNING *;
+
+UPDATE test_ref_indirection
+    SET (col_int, col_date, col_text)  = (select 7, '1974-01-01'::date, '7 ok')
+      , (col_bool) = (select true)
+RETURNING *;
+UPDATE test_dist_indirection
+    SET (col_int, col_date, col_text)  = (select 7, '1974-01-01'::date, '7 ok')
+      , (col_bool) = (select true)
+RETURNING *;
+
+UPDATE test_ref_indirection
+    SET (col_date, col_text)  = (select '1975-01-01'::date, '8 ok')
+      , (col_int) = (select 8)
+      , (col_bool) = (select false)
+RETURNING *;
+UPDATE test_dist_indirection
+    SET (col_date, col_text)  = (select '1975-01-01'::date, '8 ok')
+      , (col_int) = (select 8)
+      , (col_bool) = (select false)
+RETURNING *;
+
+--
+-- more restrictive ones, just in case we miss a wrong value
+--
+-- those should work
+UPDATE test_ref_indirection
+    SET (col_bool, col_text) = (SELECT true, '9 ok')
+RETURNING *;
+UPDATE test_dist_indirection
+    SET (col_bool, col_text) = (SELECT true, '9 ok')
+RETURNING *;
+
+UPDATE test_ref_indirection
+    SET (col_bool, col_text) = (SELECT false, '10 ok')
+WHERE id = 1
+RETURNING *;
+UPDATE test_dist_indirection
+    SET (col_bool, col_text) = (SELECT false, '10 ok')
+WHERE id = 1
+RETURNING *;
+
+UPDATE test_ref_indirection
+    SET (col_text, col_bool) = (SELECT '11 ok', true)
+RETURNING *;
+UPDATE test_dist_indirection
+    SET (col_text, col_bool) = (SELECT '11 ok', true)
+RETURNING *;
+
+UPDATE test_ref_indirection
+    SET (col_text, col_bool) = (SELECT '12 ok', false)
+WHERE id = 2
+RETURNING *;
+UPDATE test_dist_indirection
+    SET (col_text, col_bool) = (SELECT '12 ok', false)
+WHERE id = 2
+RETURNING *;
+
+-- several updates in CTE shoult not work
+with qq3 as (
+    update test_ref_indirection
+    SET (col_text, col_bool)
+      = (SELECT '13', true)
+    where id = 3
+    returning *
+),
+qq4 as (
+    update test_ref_indirection
+    SET (col_text, col_bool)
+      = (SELECT '14', false)
+    where id = 4
+    returning *
+)
+select * from qq3 union all select * from qq4;
+with qq3 as (
+    update test_dist_indirection
+    SET (col_text, col_bool)
+      = (SELECT '13', true)
+    where id = 3
+    returning *
+),
+qq4 as (
+    update test_dist_indirection
+    SET (col_text, col_bool)
+      = (SELECT '14', false)
+    where id = 4
+    returning *
+)
+select * from qq3 union all select * from qq4;
+
+DROP TABLE test_dist_indirection;
+DROP TABLE test_dist_indirection_new;
+DROP TABLE test_ref_indirection;
+DROP TABLE test_ref_indirection_new;
+
+-- https://github.com/citusdata/citus/issues/4092
+CREATE TABLE update_test (
+    a   INT DEFAULT 10,
+    b   INT,
+    c   TEXT
+);
+
+SELECT create_reference_table('update_test');
+INSERT INTO update_test VALUES (11, 41, 'car');
+INSERT INTO update_test VALUES (100, 20, 'bike');
+INSERT INTO update_test VALUES (100, 20, 'tractor');
+SELECT * FROM update_test;
+
+UPDATE update_test
+SET (b,a) = (select a,b from update_test where b = 41 and c = 'car')
+WHERE a = 100 AND b = 20
+RETURNING *;
+
+-- Test that multiple out of order columns and multiple sublinks are handled correctly.
+CREATE TABLE upd2_test (a1 int, b1 int, c1 int, d1 int, e1 int, f1 int, g1 int);
+SELECT create_reference_table('upd2_test');
+
+INSERT INTO upd2_test SELECT 1, 1, 1, 1, 1, 1, 1 FROM generate_series(1,5) c(i);
+
+UPDATE upd2_test set (b1, a1) = (SELECT 200, 100), (g1, f1, e1) = (SELECT 700, 600, 500), (d1, c1) = (SELECT 400, 300);
+SELECT * FROM upd2_test;
+
+UPDATE upd2_test set (g1, a1) = (SELECT 77, 11), (f1, b1) = (SELECT 66, 22), (e1, c1) = (SELECT 55, 33), (d1) = (SELECT 44);
+SELECT * FROM upd2_test;
+
+UPDATE upd2_test set (g1, a1) = (SELECT 7, 1), (f1) = (SELECT 6), (c1, e1) = (SELECT 3, 5), (b1) = (SELECT 2), (d1) = (SELECT 4);
+SELECT * FROM upd2_test;
+
+-- Test out of order updates on distributed table
+CREATE TABLE dist_test(a1 int, b1 numeric, c1 text, d1 int);
+SELECT create_distributed_table('dist_test', 'a1');
+INSERT INTO dist_test VALUES (1, 10.0, 'xxx', 4);
+INSERT INTO dist_test VALUES (1, 10.0, 'xxx', 4);
+INSERT INTO dist_test VALUES (2, 10.0, 'xxx', 4);
+INSERT INTO dist_test VALUES (2, 10.0, 'xxx', 4);
+INSERT INTO dist_test VALUES (3, 10.0, 'xxx', 4);
+INSERT INTO dist_test VALUES (3, 10.0, 'xxx', 4);
+INSERT INTO dist_test VALUES (3, 10.0, 'xxx', 4);
+
+-- Router plan:
+UPDATE dist_test
+SET (d1, c1, b1) = (SELECT 7, 'tractor', 4.2)
+WHERE a1=1
+RETURNING *;
+
+-- Pushdown plan:
+UPDATE dist_test
+SET (d1, c1, b1) = (SELECT X, 'car', Y)
+FROM (SELECT r.a * d1 as X, r.b * b1 as Y FROM update_test r, dist_test WHERE r.c=c1) upd
+WHERE dist_test.a1 > 2
+RETURNING *;
+
+-- Test subscripting updates
+CREATE TABLE jsonb_subscript_update (id INT, data JSONB);
+SELECT create_distributed_table('jsonb_subscript_update', 'id');
+
+INSERT INTO jsonb_subscript_update VALUES (1, '{"a": 1}'), (2, '{"a": 2}');
+
+UPDATE jsonb_subscript_update
+SET data['b'] = updated_vals.b::TEXT::jsonb,
+    data['c'] = updated_vals.c::TEXT::jsonb,
+    data['d'] = updated_vals.d::TEXT::jsonb
+FROM (
+  SELECT id,
+         data['a'] AS a,
+         data['a']::NUMERIC + 1 AS b,
+         data['a']::NUMERIC + 2 AS c,
+         data['a']::NUMERIC + 3 AS d
+  FROM jsonb_subscript_update
+) updated_vals
+WHERE jsonb_subscript_update.id = updated_vals.id;
+
+SELECT * FROM jsonb_subscript_update ORDER BY 1,2;
+
+TRUNCATE jsonb_subscript_update;
+INSERT INTO jsonb_subscript_update VALUES (1, '{"a": 1}'), (2, '{"a": 2}');
+
+-- test router update with jsonb subscript
+UPDATE jsonb_subscript_update
+SET data['b'] = updated_vals.b::TEXT::jsonb,
+    data['c'] = updated_vals.c::TEXT::jsonb,
+    data['d'] = updated_vals.d::TEXT::jsonb
+FROM (
+  SELECT id,
+         data['a'] AS a,
+         data['a']::NUMERIC + 1 AS b,
+         data['a']::NUMERIC + 2 AS c,
+         data['a']::NUMERIC + 3 AS d
+  FROM jsonb_subscript_update
+) updated_vals
+WHERE jsonb_subscript_update.id = updated_vals.id
+    AND jsonb_subscript_update.id = 1;
+
+SELECT * FROM jsonb_subscript_update WHERE id = 1 ORDER BY 1,2;
+
+TRUNCATE jsonb_subscript_update;
+
+-- Test updates on nested json objects
+INSERT INTO jsonb_subscript_update VALUES (1, '{"a": {"c":20, "d" : 200}}'), (2, '{"a": {"d":10, "c" : 100}}');
+
+BEGIN;
+UPDATE jsonb_subscript_update
+SET DATA['a']['c'] = (updated_vals.d + updated_vals.a::NUMERIC)::TEXT::JSONB
+FROM
+  (SELECT id,
+          DATA['a']['c'] AS a,
+                   DATA['a']['c']::NUMERIC + 1 AS b,
+                            DATA['a']['c']::NUMERIC + 2 AS c,
+                                     DATA['a']['d']::NUMERIC + 3 AS d
+   FROM jsonb_subscript_update) updated_vals
+WHERE jsonb_subscript_update.id = updated_vals.id;
+
+SELECT * FROM jsonb_subscript_update ORDER BY 1,2;
+ROLLBACK;
+
+BEGIN;
+-- Router plan
+UPDATE jsonb_subscript_update
+SET DATA['a']['c'] = (updated_vals.d + updated_vals.a::NUMERIC)::TEXT::JSONB
+FROM
+  (SELECT id,
+          DATA['a']['c'] AS a,
+                   DATA['a']['c']::NUMERIC + 1 AS b,
+                            DATA['a']['c']::NUMERIC + 2 AS c,
+                                     DATA['a']['d']::NUMERIC + 3 AS d
+   FROM jsonb_subscript_update) updated_vals
+WHERE jsonb_subscript_update.id = updated_vals.id
+    AND jsonb_subscript_update.id = 1;
+
+SELECT * FROM jsonb_subscript_update WHERE id = 1 ORDER BY 1,2;
+ROLLBACK;
+
+TRUNCATE jsonb_subscript_update;
+INSERT INTO jsonb_subscript_update VALUES (1, '{"a": 1}'), (2, '{"a": 2}'), (4, '{"a": 4, "b": 10}');
+
+ALTER TABLE jsonb_subscript_update ADD CONSTRAINT pkey PRIMARY KEY (id, data);
+
+INSERT INTO jsonb_subscript_update VALUES (1, '{"a": 1}'), (2, '{"a": 2}')
+ON CONFLICT (id, data)
+DO UPDATE SET data['d']=(jsonb_subscript_update.data['a']::INT*100)::TEXT::JSONB,
+              data['b']=(jsonb_subscript_update.data['a']::INT*-100)::TEXT::JSONB;
+
+SELECT * FROM jsonb_subscript_update ORDER BY 1,2;
+
+CREATE TABLE nested_obj_update(id INT, data JSONB, text_col TEXT);
+SELECT create_distributed_table('nested_obj_update', 'id');
+INSERT INTO nested_obj_update VALUES
+  (1, '{"a": [1,2,3], "b": [4,5,6], "c": [7,8,9], "d": [1,2,1,2]}', '4'),
+  (2, '{"a": [10,20,30], "b": [41,51,61], "c": [72,82,92], "d": [11,21,11,21]}', '6');
+
+BEGIN;
+-- Pushdown plan
+UPDATE nested_obj_update
+SET data['a'][0] = (updated_vals.b * 1)::TEXT::JSONB,
+    data['b'][2] = (updated_vals.c * 2)::TEXT::JSONB,
+    data['c'][0] = (updated_vals.d * 3)::TEXT::JSONB,
+    text_col = (nested_obj_update.id*1000)::TEXT,
+    data['a'][0] = (text_col::INT * data['a'][0]::INT)::TEXT::JSONB,
+    data['d'][6] = (nested_obj_update.id*1)::TEXT::JSONB,
+    data['d'][4] = (nested_obj_update.id*2)::TEXT::JSONB
+FROM (
+  SELECT id,
+         data['a'][0] AS a,
+         data['b'][0]::NUMERIC + 1 AS b,
+         data['c'][0]::NUMERIC + 2 AS c,
+         data['c'][1]::NUMERIC + 3 AS d
+  FROM nested_obj_update
+) updated_vals
+WHERE nested_obj_update.id = updated_vals.id;
+
+SELECT * FROM nested_obj_update ORDER BY 1,2,3;
+ROLLBACK;
+
+BEGIN;
+-- Router plan
+UPDATE nested_obj_update
+SET data['a'][0] = (updated_vals.b * 1)::TEXT::JSONB,
+    data['b'][2] = (updated_vals.c * 2)::TEXT::JSONB,
+    data['c'][0] = (updated_vals.d * 3)::TEXT::JSONB,
+    text_col = (nested_obj_update.id*1000)::TEXT,
+    data['a'][0] = (text_col::INT * data['a'][0]::INT)::TEXT::JSONB,
+    data['d'][6] = (nested_obj_update.id*1)::TEXT::JSONB,
+    data['d'][4] = (nested_obj_update.id*2)::TEXT::JSONB
+FROM (
+  SELECT id,
+         data['a'][0] AS a,
+         data['b'][0]::NUMERIC + 1 AS b,
+         data['c'][0]::NUMERIC + 2 AS c,
+         data['c'][1]::NUMERIC + 3 AS d
+  FROM nested_obj_update
+) updated_vals
+WHERE nested_obj_update.id = updated_vals.id
+    AND nested_obj_update.id = 2;
+
+SELECT * FROM nested_obj_update WHERE id = 2 ORDER BY 1,2,3;
+ROLLBACK;
+
+-- suppress cascade messages
+SET client_min_messages to ERROR;
+DROP SCHEMA multi_update_select CASCADE;
+RESET client_min_messages;
+

src/test/regress/sql/stat_counters.sql

@@ -476,13 +476,11 @@ CALL exec_query_and_check_query_counters($$
 );
 
 -- same with explain analyze
---
--- this time, query_execution_multi_shard is incremented twice because of #4212
 CALL exec_query_and_check_query_counters($$
     EXPLAIN (ANALYZE)
     SELECT * FROM (SELECT * FROM dist_table OFFSET 0) q
     $$,
-    1, 2
+    1, 1
 );
 
 CALL exec_query_and_check_query_counters($$
@@ -807,9 +805,6 @@ CALL exec_query_and_check_query_counters($$
 -- A similar one but without the insert, so we would normally expect 2 increments
 -- for query_execution_single_shard and 2 for query_execution_multi_shard instead
 -- of 3 since the insert is not there anymore.
---
--- But this time we observe more counter increments because we execute the subplans
--- twice because of #4212.
 CALL exec_query_and_check_query_counters($$
     EXPLAIN (ANALYZE)
     -- single-shard subplan (whole cte)
@@ -823,7 +818,7 @@ CALL exec_query_and_check_query_counters($$
     FROM (SELECT * FROM dist_table_1 ORDER BY a LIMIT 16) q -- multi-shard subplan (subquery q)
     JOIN cte ON q.a = cte.a
     $$,
-    3, 4
+    2, 2
 );
 
 -- safe to push-down

src/test/regress/sql/subscripting_op.sql

@@ -0,0 +1,93 @@
+\set VERBOSITY terse
+
+SET citus.next_shard_id TO 1520000;
+
+CREATE SCHEMA subscripting_op;
+SET search_path TO subscripting_op;
+
+CREATE TABLE arr_subs_update(id INT, arr INT[], text_col TEXT, int_col_1 INT, int_col_2 INT);
+SELECT create_distributed_table('arr_subs_update', 'id');
+INSERT INTO arr_subs_update
+  VALUES (1, '{1,2,3}', 'foo', 50, 60),
+         (2, '{4,5,6}', 'bar', 60, 70),
+         (3, '{7,8,9}', 'baz', 70, 80);
+
+BEGIN;
+UPDATE arr_subs_update
+SET arr[1] = updated_vals.b,
+    arr[3] = updated_vals.d,
+    int_col_2 = 400,
+    arr[2] = updated_vals.c
+FROM (
+  SELECT id,
+         arr[0] AS a,
+         arr[1]::NUMERIC + 1 AS b,
+         arr[2]::NUMERIC + 2 AS c,
+         arr[3]::NUMERIC + 3 AS d
+  FROM arr_subs_update
+) updated_vals
+WHERE arr_subs_update.id = updated_vals.id;
+
+SELECT * FROM arr_subs_update ORDER BY 1,2,3,4;
+
+ROLLBACK;
+
+BEGIN;
+-- Test fast path router plan for subscripting update
+UPDATE arr_subs_update
+SET arr[1] = updated_vals.b,
+    arr[3] = updated_vals.d,
+    int_col_2 = 400,
+    arr[2] = updated_vals.c
+FROM (
+  SELECT id,
+         arr[0] AS a,
+         arr[1]::NUMERIC + 1 AS b,
+         arr[2]::NUMERIC + 2 AS c,
+         arr[3]::NUMERIC + 3 AS d
+  FROM arr_subs_update
+) updated_vals
+WHERE arr_subs_update.id = updated_vals.id
+  AND arr_subs_update.id = 1;
+
+SELECT * FROM arr_subs_update
+WHERE id=1 ORDER BY 1,2,3,4;
+
+ROLLBACK;
+
+-- test if we can properly expand target list entries when there are dropped columns
+ALTER TABLE arr_subs_update DROP COLUMN int_col_1;
+
+BEGIN;
+UPDATE arr_subs_update
+SET arr[1] = updated_vals.b,
+    arr[3] = updated_vals.d,
+    int_col_2 = 400,
+    arr[2] = updated_vals.c
+FROM (
+  SELECT id,
+         arr[0] AS a,
+         arr[1]::NUMERIC + 1 AS b,
+         arr[2]::NUMERIC + 2 AS c,
+         arr[3]::NUMERIC + 3 AS d
+  FROM arr_subs_update
+) updated_vals
+WHERE arr_subs_update.id = updated_vals.id;
+
+SELECT * FROM arr_subs_update ORDER BY 1,2,3,4;
+
+ROLLBACK;
+
+TRUNCATE arr_subs_update;
+INSERT INTO arr_subs_update VALUES (1, '{1,2,3}', 'foo', 60), (2, '{4,5,6}', 'bar', 70);
+
+ALTER TABLE arr_subs_update ADD CONSTRAINT pkey PRIMARY KEY (id, arr);
+
+INSERT INTO arr_subs_update VALUES (1, '{1,2,3}')
+ON CONFLICT (id, arr)
+DO UPDATE SET arr[0]=100, arr[1]=200, arr[5]=500;
+
+SELECT * FROM arr_subs_update ORDER BY 1,2,3,4;
+
+SET client_min_messages TO WARNING;
+DROP SCHEMA subscripting_op CASCADE;

src/test/regress/sql/union_pushdown.sql

@@ -1109,5 +1109,49 @@ SELECT k, COUNT(*) FROM v GROUP BY k ORDER BY k;
 $$);
 
 
+CREATE TABLE dist1 (a int, b int);
+CREATE TABLE dist2 (a int, b int);
+SET citus.shard_count to 4;
+SELECT create_distributed_table('dist1', 'a');
+SELECT create_distributed_table('dist2', 'a');
+INSERT INTO dist1 VALUES (1, 1), (2, 1), (3, 1), (4, 1), (5, 1);
+INSERT INTO dist2 VALUES (5, 2), (6, 2), (7, 2), (8, 2), (9, 2);
+
+-- safe to pushdown
+SELECT * FROM
+(
+  SELECT * FROM dist1 JOIN dist2 USING (a)
+  UNION
+  SELECT * FROM dist1 JOIN dist2 USING (a)
+) AS t1 ORDER BY 1;
+
+-- not safe to pushdown, the distribution key from the outer part of the outer join is not in the target list
+SELECT * FROM
+(
+  SELECT dist2.a FROM dist1 LEFT JOIN dist2 USING (a)
+  UNION
+  SELECT dist2.a FROM dist2
+) AS t1 ORDER BY 1;
+
+set client_min_messages to DEBUG3;
+-- not safe to pushdown, as is, sub-plan is generated
+-- the distribution key from the outer part of the outer join is not in the target list
+SELECT * FROM
+(
+  SELECT dist1.a FROM dist1 RIGHT JOIN dist2 USING (a)
+  UNION
+  SELECT dist2.a FROM dist2
+) AS t1 ORDER BY 1;
+
+-- safe to pushdown, the distribution key from the outer side of the RIGHT join is in the target list
+SELECT * FROM
+(
+  SELECT dist2.a
+    FROM dist1 RIGHT JOIN dist2 USING (a)
+  UNION
+  SELECT dist2.a FROM dist2
+) AS t1
+ORDER BY 1;
+
 SET client_min_messages TO WARNING;
 DROP SCHEMA union_pushdown CASCADE;