Refactor RecursivelyPlanSubqueriesAndCTEs() to make it ready

to work with subqueries

src/backend/distributed/planner/distributed_planner.c

@@ -595,6 +595,7 @@ CreateDistributedSelectPlan(uint64 planId, Query *originalQuery, Query *query,
 	MultiTreeRoot *logicalPlan = NULL;
 	DeferredErrorMessage *error = NULL;
 	List *subPlanList = NIL;
+	RecursivePlanningContext context;
 
 	/*
 	 * For select queries we, if router executor is enabled, first try to
@@ -648,8 +649,12 @@ CreateDistributedSelectPlan(uint64 planId, Query *originalQuery, Query *query,
 	 * Plan subqueries and CTEs that cannot be pushed down by recursively
 	 * calling the planner and add the resulting plans to subPlanList.
 	 */
-	error = RecursivelyPlanSubqueriesAndCTEs(originalQuery, plannerRestrictionContext,
-											 planId, &subPlanList);
+	context.level = 0;
+	context.planId = planId;
+	context.subPlanList = NIL;
+	context.plannerRestrictionContext = plannerRestrictionContext;
+
+	error = RecursivelyPlanSubqueriesAndCTEs(originalQuery, &context);
 	if (error != NULL)
 	{
 		RaiseDeferredError(error, ERROR);
@@ -663,6 +668,7 @@ CreateDistributedSelectPlan(uint64 planId, Query *originalQuery, Query *query,
 	 * with an original query. In that case, we would only have to filter the
 	 * planner restriction context.
 	 */
+	subPlanList = context.subPlanList;
 	if (list_length(subPlanList) > 0)
 	{
 		Query *newQuery = copyObject(originalQuery);

src/backend/distributed/planner/recursive_planning.c

@@ -73,19 +73,6 @@
 #include "utils/guc.h"
 
 
-/*
- * RecursivePlanningContext is used to recursively plan subqueries
- * and CTEs, pull results to the coordinator, and push it back into
- * the workers.
- */
-typedef struct RecursivePlanningContext
-{
-	int level;
-	uint64 planId;
-	List *subPlanList;
-	PlannerRestrictionContext *plannerRestrictionContext;
-} RecursivePlanningContext;
-
 /*
  * CteReferenceWalkerContext is used to collect CTE references in
  * CteReferenceListWalker.
@@ -133,17 +120,9 @@ static Query * BuildSubPlanResultQuery(Query *subquery, uint64 planId, uint32 su
  * subplans will be added to subPlanList.
  */
 DeferredErrorMessage *
-RecursivelyPlanSubqueriesAndCTEs(Query *query,
-								 PlannerRestrictionContext *plannerRestrictionContext,
-								 uint64 planId, List **subPlanList)
+RecursivelyPlanSubqueriesAndCTEs(Query *query, RecursivePlanningContext *context)
 {
 	DeferredErrorMessage *error = NULL;
-	RecursivePlanningContext context;
-
-	context.level = 0;
-	context.planId = planId;
-	context.subPlanList = NIL;
-	context.plannerRestrictionContext = plannerRestrictionContext;
 
 	error = RecursivelyPlanCTEs(query, &context);
 	if (error != NULL)
@@ -166,9 +145,8 @@ RecursivelyPlanSubqueriesAndCTEs(Query *query,
 		return NULL;
 	}
 
-	/* XXX: plan subqueries */
-
-	*subPlanList = context.subPlanList;
+	/* descend into subqueries */
+	query_tree_walker(query, RecursivelyPlanSubqueryWalker, context, 0);
 
 	return NULL;
 }

src/include/distributed/distributed_planner.h

@@ -92,9 +92,6 @@ extern bool IsModifyDistributedPlan(struct DistributedPlan *distributedPlan);
 extern bool IsMultiTaskPlan(struct DistributedPlan *distributedPlan);
 extern bool IsMultiShardModifyPlan(struct DistributedPlan *distributedPlan);
 extern RangeTblEntry * RemoteScanRangeTableEntry(List *columnNameList);
-extern char * GenerateResultId(uint64 planId, uint32 subPlanId);
-
-
 extern int GetRTEIdentity(RangeTblEntry *rte);
 
 #endif /* DISTRIBUTED_PLANNER_H */

src/include/distributed/recursive_planning.h

@@ -18,11 +18,23 @@
 #include "nodes/relation.h"
 
 
+/*
+ * RecursivePlanningContext is used to recursively plan subqueries
+ * and CTEs, pull results to the coordinator, and push it back into
+ * the workers.
+ */
+typedef struct RecursivePlanningContext
+{
+	int level;
+	uint64 planId;
+	List *subPlanList;
+	PlannerRestrictionContext *plannerRestrictionContext;
+} RecursivePlanningContext;
+
+
 extern DeferredErrorMessage * RecursivelyPlanSubqueriesAndCTEs(Query *query,
-															   PlannerRestrictionContext *
-															   plannerRestrictionContext,
-															   uint64 planId,
-															   List **subPlanList);
+															   RecursivePlanningContext *
+															   context);
 extern char * GenerateResultId(uint64 planId, uint32 subPlanId);