Merge e0a3d22662 into 5deaf9a616

src/backend/distributed/executor/adaptive_executor.c

@@ -630,6 +630,7 @@ typedef struct TaskPlacementExecution
 	instr_time endTime;
 } TaskPlacementExecution;
 
+extern MemoryContext SubPlanExplainAnalyzeContext;
 
 /* local functions */
 static DistributedExecution * CreateDistributedExecution(RowModifyLevel modLevel,
@@ -760,7 +761,7 @@ AdaptiveExecutorPreExecutorRun(CitusScanState *scanState)
 	 */
 	LockPartitionsForDistributedPlan(distributedPlan);
 
-	ExecuteSubPlans(distributedPlan);
+	ExecuteSubPlans(distributedPlan, RequestedForExplainAnalyze(scanState));
 
 	scanState->finishedPreScan = true;
 }

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/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/subplan_execution.c

@@ -30,13 +30,21 @@ 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;
+SubPlanExplainOutput *SubPlanExplainAnalyzeOutput;
+extern int 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 +55,19 @@ 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);
 
@@ -61,6 +82,13 @@ ExecuteSubPlans(DistributedPlan *distributedPlan)
 	DistributedSubPlan *subPlan = NULL;
 	foreach_declared_ptr(subPlan, subPlanList)
 	{
+		/*
+		 * Save the EXPLAIN ANALYZE output(s) to be extracted later
+		 * in ExplainSubPlans()
+		 */
+		MemSet(subPlan->totalExplainOutput, 0, sizeof(subPlan->totalExplainOutput));
+		SubPlanExplainAnalyzeOutput = subPlan->totalExplainOutput;
+
 		PlannedStmt *plannedStmt = subPlan->plan;
 		uint32 subPlanId = subPlan->subPlanId;
 		ParamListInfo params = NULL;
@@ -79,7 +107,17 @@ ExecuteSubPlans(DistributedPlan *distributedPlan)
 
 		TimestampTz startTimestamp = GetCurrentTimestamp();
 
-		ExecutePlanIntoDestReceiver(plannedStmt, params, copyDest);
+		PG_TRY();
+		{
+			ExecutePlanIntoDestReceiver(plannedStmt, params, copyDest);
+		}
+		PG_CATCH();
+		{
+			SubPlanExplainAnalyzeContext = NULL;
+			PG_RE_THROW();
+		}
+		PG_END_TRY();
+
 
 		/*
 		 * EXPLAIN ANALYZE instrumentations. Calculating these are very light-weight,
@@ -98,6 +136,10 @@ ExecuteSubPlans(DistributedPlan *distributedPlan)
 		subPlan->writeLocalFile = entry->writeLocalFile;
 
 		SubPlanLevel--;
+		subPlan->numTasksOutput = NumTasksOutput;
+		NumTasksOutput = 0;
 		FreeExecutorState(estate);
 	}
+
+	SubPlanExplainAnalyzeContext = NULL;
 }

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"
@@ -68,6 +69,7 @@
 #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"
@@ -78,6 +80,7 @@
 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
@@ -85,6 +88,8 @@ int ExplainAnalyzeSortMethod = EXPLAIN_ANALYZE_SORT_BY_TIME;
  */
 static char *SavedExplainPlan = NULL;
 static double SavedExecutionDurationMillisec = 0.0;
+extern SubPlanExplainOutput *SubPlanExplainAnalyzeOutput;
+int NumTasksOutput = 0;
 
 /* struct to save explain flags */
 typedef struct
@@ -161,6 +166,7 @@ static void ExplainIndentText(ExplainState *es);
 static void ExplainPrintSerialize(ExplainState *es,
 								  SerializeMetrics *metrics);
 static SerializeMetrics GetSerializationMetrics(DestReceiver *dest);
+static void ExtractAnalyzeStats(DistributedSubPlan *subPlan, PlanState *planState);
 
 /*
  * DestReceiver functions for SERIALIZE option
@@ -210,7 +216,8 @@ 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,
@@ -251,6 +258,7 @@ 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 void ParseExplainAnalyzeOutput(char *explainOutput, Instrumentation *instr);
 
 
 /* exports for SQL callable functions */
@@ -427,6 +435,63 @@ 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 || !IsA(planState, CustomScanState))
+	{
+		return;
+	}
+
+	/* Inject the earlier executed results into the newly created tasks */
+	if (subPlan->numTasksOutput)
+	{
+		DistributedPlan *newdistributedPlan =
+			((CitusScanState *) planState)->distributedPlan;
+
+		ListCell *lc;
+		int idx = 0;
+
+		/* We need to extract this from the explain output of workers */
+		Instrumentation *instr = planState->instrument;
+		memset(instr, 0, sizeof(Instrumentation));
+
+		foreach(lc, newdistributedPlan->workerJob->taskList)
+		{
+			if (subPlan->totalExplainOutput[idx].explainOutput &&
+				idx < subPlan->numTasksOutput)
+			{
+				/*
+				 * Now feed the earlier saved output, which will be used
+				 * by RemoteExplain() when printing tasks
+				 */
+				Task *task = (Task *) lfirst(lc);
+				MemoryContext taskContext = GetMemoryChunkContext(task);
+
+				task->totalReceivedTupleData =
+					subPlan->totalExplainOutput[idx].totalReceivedTupleData;
+				task->fetchedExplainAnalyzeExecutionDuration =
+					subPlan->totalExplainOutput[idx].executionDuration;
+				task->fetchedExplainAnalyzePlan =
+					MemoryContextStrdup(taskContext,
+										subPlan->totalExplainOutput[idx].explainOutput);
+				ParseExplainAnalyzeOutput(task->fetchedExplainAnalyzePlan, instr);
+
+				subPlan->totalExplainOutput[idx].explainOutput = NULL;
+			}
+
+			idx++;
+		}
+
+		planState->instrument->nloops = 1; /* TODO */
+	}
+}
+
+
 /*
  * ExplainSubPlans generates EXPLAIN output for subplans for CTEs
  * and complex subqueries. Because the planning for these queries
@@ -445,7 +510,6 @@ ExplainSubPlans(DistributedPlan *distributedPlan, ExplainState *es)
 	{
 		DistributedSubPlan *subPlan = (DistributedSubPlan *) lfirst(subPlanCell);
 		PlannedStmt *plan = subPlan->plan;
-		IntoClause *into = NULL;
 		ParamListInfo params = NULL;
 
 		/*
@@ -453,7 +517,7 @@ ExplainSubPlans(DistributedPlan *distributedPlan, ExplainState *es)
 		 * for now we put an empty string, which is valid according to postgres.
 		 */
 		char *queryString = pstrdup("");
-		instr_time planduration;
+		instr_time planDuration;
 		BufferUsage bufusage_start,
 					bufusage;
 
@@ -518,7 +582,7 @@ ExplainSubPlans(DistributedPlan *distributedPlan, ExplainState *es)
 			ExplainPropertyText("Result destination", destination->data, es);
 		}
 
-		INSTR_TIME_SET_ZERO(planduration);
+		INSTR_TIME_SET_ZERO(planDuration);
 
 		/* calc differences of buffer counters. */
 		if (es->buffers)
@@ -529,6 +593,10 @@ ExplainSubPlans(DistributedPlan *distributedPlan, ExplainState *es)
 
 		ExplainOpenGroup("PlannedStmt", "PlannedStmt", false, es);
 
+		/* TODO: Do we really need dest and bound params when not executing? */
+		DestReceiver *dest = None_Receiver;
+		double executionDurationMillisec = 0.0;
+
 #if PG_VERSION_NUM >= PG_VERSION_17
 		if (es->memory)
 		{
@@ -536,12 +604,24 @@ ExplainSubPlans(DistributedPlan *distributedPlan, ExplainState *es)
 			MemoryContextMemConsumed(planner_ctx, &mem_counters);
 		}
 
-		ExplainOnePlan(plan, into, es, queryString, params, NULL, &planduration,
+		/* calc differences of buffer counters. */
-					   (es->buffers ? &bufusage : NULL),
+		if (es->buffers)
-					   (es->memory ? &mem_counters : NULL));
+		{
+			memset(&bufusage, 0, sizeof(BufferUsage));
+			BufferUsageAccumDiff(&bufusage, &pgBufferUsage, &bufusage_start);
+		}
+
+		/* do the actual EXPLAIN ANALYZE */
+		ExplainWorkerPlan(plan, subPlan, dest, es, queryString, params, NULL,
+						  &planDuration,
+						  (es->buffers ? &bufusage : NULL),
+						  (es->memory ? &mem_counters : NULL),
+						  &executionDurationMillisec);
 #else
-		ExplainOnePlan(plan, into, es, queryString, params, NULL, &planduration,
+
-					   (es->buffers ? &bufusage : NULL));
+		/* do the actual EXPLAIN ANALYZE */
+		ExplainWorkerPlan(plan, subPlan, dest, es, queryString, params, NULL,
+						  &planDuration, &executionDurationMillisec);
 #endif
 
 		ExplainCloseGroup("PlannedStmt", "PlannedStmt", false, es);
@@ -1359,7 +1439,7 @@ 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),
@@ -1367,7 +1447,7 @@ worker_save_query_explain_analyze(PG_FUNCTION_ARGS)
 #else
 
 	/* do the actual EXPLAIN ANALYZE */
-	ExplainWorkerPlan(plan, tupleStoreDest, es, queryString, boundParams, NULL,
+	ExplainWorkerPlan(plan, NULL, tupleStoreDest, es, queryString, boundParams, NULL,
 					  &planDuration, &executionDurationMillisec);
 #endif
 
@@ -1621,6 +1701,11 @@ ExplainAnalyzeDestPutTuple(TupleDestination *self, Task *task,
 		originalTupDest->putTuple(originalTupDest, task, placementIndex, 0, heapTuple,
 								  tupleLibpqSize);
 		tupleDestination->originalTask->totalReceivedTupleData += tupleLibpqSize;
+		if (SubPlanExplainAnalyzeContext && NumTasksOutput < MAX_ANALYZE_OUTPUT)
+		{
+			SubPlanExplainAnalyzeOutput[NumTasksOutput].totalReceivedTupleData =
+				tupleDestination->originalTask->totalReceivedTupleData;
+		}
 	}
 	else if (queryNumber == 1)
 	{
@@ -1670,6 +1755,17 @@ ExplainAnalyzeDestPutTuple(TupleDestination *self, Task *task,
 			placementIndex;
 		tupleDestination->originalTask->fetchedExplainAnalyzeExecutionDuration =
 			fetchedExplainAnalyzeExecutionDuration;
+
+		/* We should build tupleDestination in subPlan similar to the above */
+		if (SubPlanExplainAnalyzeContext && NumTasksOutput < MAX_ANALYZE_OUTPUT)
+		{
+			SubPlanExplainAnalyzeOutput[NumTasksOutput].explainOutput =
+				MemoryContextStrdup(SubPlanExplainAnalyzeContext,
+									fetchedExplainAnalyzePlan);
+			SubPlanExplainAnalyzeOutput[NumTasksOutput].executionDuration =
+				fetchedExplainAnalyzeExecutionDuration;
+			NumTasksOutput++;
+		}
 	}
 	else
 	{
@@ -1732,7 +1828,14 @@ 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);
 }
 
 
@@ -2045,6 +2148,19 @@ ExplainOneQuery(Query *query, int cursorOptions,
 }
 
 
+static bool
+extract_analyze_walker(PlanState *ps, void *ctx)
+{
+	DistributedSubPlan *subplan = (DistributedSubPlan *) ctx;
+
+	/* call your extractor on every node */
+	ExtractAnalyzeStats(subplan, ps);
+
+	/* return false to keep recursing into children */
+	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
@@ -2059,7 +2175,7 @@ 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
@@ -2073,6 +2189,8 @@ ExplainWorkerPlan(PlannedStmt *plannedstmt, DestReceiver *dest, ExplainState *es
 	double		totaltime = 0;
 	int			eflags;
 	int			instrument_option = 0;
+	/* Never executed a sub-plan, it's already done */
+	bool executeQuery = (es->analyze && !subPlan);
 
 	Assert(plannedstmt->commandType != CMD_UTILITY);
 
@@ -2107,7 +2225,7 @@ ExplainWorkerPlan(PlannedStmt *plannedstmt, DestReceiver *dest, ExplainState *es
 								dest, params, queryEnv, instrument_option);
 
 	/* Select execution options */
-	if (es->analyze)
+	if (executeQuery)
 		eflags = 0;				/* default run-to-completion flags */
 	else
 		eflags = EXEC_FLAG_EXPLAIN_ONLY;
@@ -2116,7 +2234,7 @@ 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;
 
@@ -2132,6 +2250,14 @@ ExplainWorkerPlan(PlannedStmt *plannedstmt, DestReceiver *dest, ExplainState *es
 
 	ExplainOpenGroup("Query", NULL, true, es);
 
+	if (subPlan)
+	{
+		ExtractAnalyzeStats(subPlan, queryDesc->planstate);
+		/* …then, once you’ve got your top‐level PlanState (e.g. planstate of your subplan): */
+		planstate_tree_walker(queryDesc->planstate, extract_analyze_walker, (void *) subPlan);
+
+	}
+
 	/* Create textual dump of plan tree */
 	ExplainPrintPlan(es, queryDesc);
 
@@ -2211,7 +2337,7 @@ 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);
@@ -2248,6 +2374,115 @@ elapsed_time(instr_time *starttime)
 }
 
 
+/*
+ * ParseExplainAnalyzeOutput
+ *
+ * Parses the output of an EXPLAIN ANALYZE run to extract ANALYZE statistics
+ * and other instrumentation data.
+ *
+ * Parameters:
+ *   explainOutput  - a null-terminated string containing the raw EXPLAIN ANALYZE output
+ *   instr          - pointer to an Instrumentation struct to accumulate parsed metrics
+ *
+ * Behavior:
+ *   - Validates inputs and returns immediately if either pointer is NULL.
+ *   - Tokenizes the output on spaces, parentheses, and newlines.
+ *   - Populates the instr-><..> fields.
+ *
+ * Notes:
+ *   - Caller must free or manage the memory for explainOutput.
+ *   - Parsing is case-sensitive and assumes standard EXPLAIN ANALYZE formatting.
+ */
+static void
+ParseExplainAnalyzeOutput(char *explainOutput, Instrumentation *instr)
+{
+	/* elog(NOTICE, "Parsing :%s ", explainOutput); */
+	char *token, *saveptr;
+
+	/* Validate input */
+	if (explainOutput == NULL || instr == NULL)
+		return;
+
+	char *line = pstrdup(explainOutput);
+
+	bool inWal = false;
+	bool inResult = false;
+
+	/* split on spaces, parentheses or newlines */
+	for (token = strtok_r(line, " ()\n", &saveptr);
+		 token != NULL;
+		 token = strtok_r(NULL, " ()\n", &saveptr))
+	{
+		if (strcmp(token, "WAL:") == 0)
+		{
+			inWal = true;
+			continue;
+		}
+
+		if (strcmp(token, "Result") == 0)
+		{
+			inResult = true;
+			continue;
+		}
+
+		/* Reset Result flag when we see "actual" - but only skip if we're in Result mode */
+		if (strcmp(token, "actual") == 0)
+		{
+			/* If we were in Result mode, the next tokens should be skipped */
+			/* If we weren't in Result mode, continue normally */
+			continue;
+		}
+
+		if (inWal)
+		{
+			if (strncmp(token, "records=", 8) == 0)
+				instr->walusage.wal_records += strtoul(token + 8, NULL, 10);
+			else if (strncmp(token, "bytes=", 6) == 0)
+			{
+				instr->walusage.wal_bytes += strtoul(token + 6, NULL, 10);
+				/* once we've seen bytes=, we can leave WAL mode */
+				inWal = false;
+			}
+			continue;
+		}
+
+		/* Skip Result node's actual timing data */
+		if (inResult)
+		{
+			if (strncmp(token, "time=", 5) == 0 ||
+				strncmp(token, "rows=", 5) == 0 ||
+				strncmp(token, "loops=", 6) == 0)
+			{
+				/* If this is loops=, we've seen all Result data */
+				if (strncmp(token, "loops=", 6) == 0)
+					inResult = false;
+				continue;
+			}
+		}
+
+		if (strncmp(token, "time=", 5) == 0)
+		{
+			/* token is "time=X..Y" */
+			char *timeStr = token + 5;
+			char *doubleDot = strstr(timeStr, "..");
+			if (doubleDot)
+			{
+				*doubleDot = '\0';
+				instr->startup += strtod(timeStr, NULL) / 1000.0;
+				instr->total += strtod(doubleDot + 2, NULL) / 1000.0;
+			}
+		}
+		else if (strncmp(token, "rows=", 5) == 0)
+		{
+			instr->ntuples += strtol(token + 5, NULL, 10);
+			break; /* We are done for this Task */
+		}
+	}
+
+	pfree(line);
+}
+
+
 #if PG_VERSION_NUM >= PG_VERSION_17
 /*
  * Return whether show_buffer_usage would have anything to print, if given

src/backend/distributed/utils/citus_copyfuncs.c

@@ -147,6 +147,27 @@ 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);
+
+	MemSet(newnode->totalExplainOutput, 0, sizeof(newnode->totalExplainOutput));
+
+	/* copy each SubPlanExplainOutput element */
+	for (int i = 0; i < MAX_ANALYZE_OUTPUT; 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);
 }
 
 

src/backend/distributed/utils/citus_outfuncs.c

@@ -215,6 +215,46 @@ 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 < MAX_ANALYZE_OUTPUT; i++)
+	{
+		const SubPlanExplainOutput *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, ')');
+	}
+
+	WRITE_INT_FIELD(numTasksOutput);
+
+	appendStringInfoChar(str, ']');
 }
 
 void

src/include/distributed/distributed_planner.h

@@ -28,6 +28,7 @@
 
 #define CURSOR_OPT_FORCE_DISTRIBUTED 0x080000
 
+#define MAX_ANALYZE_OUTPUT 32
 
 /* level of planner calls */
 extern int PlannerLevel;

src/include/distributed/multi_physical_planner.h

@@ -474,6 +474,17 @@ typedef struct DistributedPlan
 } DistributedPlan;
 
 
+/*
+ *
+ */
+typedef struct SubPlanExplainOutput
+{
+	char *explainOutput;
+	double executionDuration;
+	uint64 totalReceivedTupleData;
+} SubPlanExplainOutput;
+
+
 /*
  * DistributedSubPlan contains a subplan of a distributed plan. Subplans are
  * executed before the distributed query and their results are written to
@@ -492,6 +503,8 @@ typedef struct DistributedSubPlan
 	uint32 remoteWorkerCount;
 	double durationMillisecs;
 	bool writeLocalFile;
+	SubPlanExplainOutput totalExplainOutput[MAX_ANALYZE_OUTPUT];
+	uint32 numTasksOutput;
 } DistributedSubPlan;
 
 

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/test/regress/expected/multi_explain.out

@@ -2492,12 +2492,12 @@ 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)
                           ->  Seq Scan on dist_table_570017 dist_table (actual rows=8 loops=1)
@@ -3228,6 +3228,47 @@ 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
+-- 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/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/sql/multi_explain.sql

@@ -1166,6 +1166,26 @@ 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;
+
+-- 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/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