fix check for outer rel to take mapped varno's into account

src/backend/distributed/executor/citus_custom_scan.c

@@ -608,11 +608,6 @@ AdaptiveExecutorCreateScan(CustomScan *scan)
 	scanState->finishedPreScan = false;
 	scanState->finishedRemoteScan = false;
 
-	int numParams = NumberOfParameters((Node *) scan->custom_exprs);
-	scanState->numParameters = numParams;
-	scanState->paramValues = palloc0(scanState->numParameters * sizeof(Datum));
-	scanState->paramNulls = palloc0(scanState->numParameters * sizeof(bool));
-
 	return (Node *) scanState;
 }
 
@@ -721,21 +716,6 @@ CitusReScan(CustomScanState *node)
 	EState *executorState = ScanStateGetExecutorState(scanState);
 	ParamListInfo paramListInfo = executorState->es_param_list_info;
 
-	/* for all the changed parameters, store them locally so we can use them during query dispatch */
-	int x = -1;
-	while ((x = bms_next_member(node->ss.ps.chgParam, x)) >= 0)
-	{
-		/* make sure the parameter that changed is within bounds */
-		Assert(scanState->numParameters > x);
-
-		/* copy the parameter information into local state*/
-		ParamExecData paramExecData = executorState->es_param_exec_vals[x];
-		scanState->paramValues[x] = paramExecData.value;
-		scanState->paramNulls[x] = paramExecData.isnull;
-		
-		ereport(NOTICE, (errmsg("changed parameter: %d", x)));
-	}
-
 	if (paramListInfo != NULL && !workerJob->parametersInJobQueryResolved)
 	{
 		ereport(ERROR, (errcode(ERRCODE_FEATURE_NOT_SUPPORTED),

src/backend/distributed/planner/path_based_planner.c

@@ -66,7 +66,7 @@ static CustomPath * WrapTableAccessWithDistributedUnion(Path *originalPath, uint
 														Expr *partitionValue, Oid
 														sampleRelid, List *subPaths);
 static Query * GetQueryFromPath(PlannerInfo *root, Path *path, List *tlist,
-								List *clauses);
+								List *clauses, Index **varnoMapping);
 static List * ShardIntervalListToRelationShardList(List *shardIntervalList);
 static List * OptimizeJoinPath(PlannerInfo *root, Path *originalPath);
 static List * BroadcastOuterJoinPath(PlannerInfo *root, Path *originalPath);
@@ -148,8 +148,15 @@ WrapTableAccessWithDistributedUnion(Path *originalPath, uint32 colocationId,
 }
 
 
+typedef struct TransformVarToParamExternMutatorContext
+{
+	PlannerInfo *root;
+	Index *varnoMapping;
+} TransformVarToParamExternMutatorContext;
+
+
 static Node *
-TransformVarToParamExternMutator(Node *node, PlannerInfo *root)
+TransformVarToParamExternMutator(Node *node, TransformVarToParamExternMutatorContext *context)
 {
 	if (node == NULL)
 	{
@@ -160,13 +167,20 @@ TransformVarToParamExternMutator(Node *node, PlannerInfo *root)
 	{
 		Var *var = castNode(Var, node);
 
+		Index originalVarNo = context->varnoMapping[var->varno];
+		if (originalVarNo == 0)
+		{
+			/* no mapping was required */
+			originalVarNo = var->varno;
+		}
+		Assert(originalVarNo > 0);
 		/* If not to be replaced, we can just return the Var unmodified */
-		if (!bms_is_member(var->varno, root->curOuterRels))
+		if (!bms_is_member(originalVarNo, context->root->curOuterRels))
 		{
 			return (Node *) var;
 		}
 
-		Param *paramExec = replace_nestloop_param_var(root, var);
+		Param *paramExec = replace_nestloop_param_var(context->root, var);
 
 		/* TODO: figure out which Var's to replace by which parameters*/
 		/* TODO: hack - insert param 1 for now */
@@ -188,12 +202,24 @@ TransformVarToParamExternMutator(Node *node, PlannerInfo *root)
 
 		return (Node *) query_tree_mutator((Query *) node,
 									 TransformVarToParamExternMutator,
-									 (void *) root,
+									 (void *) context,
 									 0);
 	}
 
 	return expression_tree_mutator(node, TransformVarToParamExternMutator,
-								   (void *) root);
+								   (void *) context);
+}
+
+
+static Query *
+TransformVarToParamExtern(Query *query, PlannerInfo *root, Index *varnoMapping)
+{
+	TransformVarToParamExternMutatorContext context = {
+			root,
+			varnoMapping
+	};
+
+	return castNode(Query, TransformVarToParamExternMutator((Node *) query, &context));
 }
 
 
@@ -212,7 +238,8 @@ CreateDistributedUnionPlan(PlannerInfo *root,
 
 	ShardInterval *shardInterval = NULL;
 
-	Query *q = GetQueryFromPath(root, distUnion->worker_path, tlist, clauses);
+	Index *varnoMapping = NULL; /* store mapping back for outerrel checks */
+	Query *q = GetQueryFromPath(root, distUnion->worker_path, tlist, clauses, &varnoMapping);
 
 	/*
 	 * Assume shards are colocated, any shard should suffice for now to find the initial
@@ -234,7 +261,7 @@ CreateDistributedUnionPlan(PlannerInfo *root,
 		UpdateRelationToShardNames((Node *) qc, relationShardList);
 
 		/* transform Var's for other varno's to parameters */
-		qc = castNode(Query, TransformVarToParamExternMutator((Node *) qc, root));
+		qc = TransformVarToParamExtern(qc, root, varnoMapping);
 
 		StringInfoData buf;
 		initStringInfo(&buf);
@@ -294,8 +321,8 @@ CreateDistributedUnionPlan(PlannerInfo *root,
 	/* Reduce RestrictInfo list to bare expressions; ignore pseudoconstants */
 	clauses = extract_actual_clauses(clauses, false);
 
-	plan->scan.plan.qual = clauses;
+//	plan->scan.plan.qual = clauses;
-	plan->custom_exprs = clauses;
+//	plan->custom_exprs = clauses;
 
 	return (Plan *) plan;
 }
@@ -1414,8 +1441,14 @@ ApplyPathToQuery(PlannerInfo *root, Query *query, Path *path, PathQueryInfo *inf
 }
 
 
+/*
+ * when varnoMapping is set it stores an array of varno's in the new query to the original
+ * varno's of the source query. This can later be used to understand if the var's used in
+ * this query come from an outer rel in a nested loop.
+ */
 static Query *
-GetQueryFromPath(PlannerInfo *root, Path *path, List *tlist, List *clauses)
+GetQueryFromPath(PlannerInfo *root, Path *path, List *tlist, List *clauses,
+				 Index **varnoMapping)
 {
 	PathQueryInfo info = { 0 };
 	info.varno_mapping = palloc0(sizeof(Index) * root->simple_rel_array_size);
@@ -1447,6 +1480,22 @@ GetQueryFromPath(PlannerInfo *root, Path *path, List *tlist, List *clauses)
 	}
 	q->jointree->quals = VarNoMutator(q->jointree->quals, info.varno_mapping);
 
+	if (varnoMapping)
+	{
+		/* export the reverse varno mapping */
+		int mappingSize = list_length(q->rtable);
+		*varnoMapping = palloc0(sizeof(Index) * root->simple_rel_array_size);
+		for (int i = 0; i < root->simple_rel_array_size; i++)
+		{
+			Index varno = info.varno_mapping[i];
+			if (varno == 0)
+			{
+				continue;
+			}
+			(*varnoMapping)[varno] = i;
+		}
+	}
+
 	return q;
 }
 

src/include/distributed/citus_custom_scan.h

@@ -27,10 +27,6 @@ typedef struct CitusScanState
 	MultiExecutorType executorType;   /* distributed executor type */
 	bool finishedRemoteScan;          /* flag to check if remote scan is finished */
 	Tuplestorestate *tuplestorestate; /* tuple store to store distributed results */
-
-	int numParameters;  /* number of parameters passed into node per rescan */
-	Datum *paramValues; /* array of last passed parameter values */
-	bool *paramNulls;   /* array of last passed parameter null flags*/
 } CitusScanState;