Test code, not completely working.gather3

2 files changed, 32 insertions, 11 deletions

diff --git a/src/backend/commands/explain.c b/src/backend/commands/explain.c
index 12a59a3560..ee3165b733 100644
--- a/src/backend/commands/explain.c
+++ b/src/backend/commands/explain.c
@@ -58,7 +58,7 @@ static double elapsed_time(instr_time *starttime);
 static bool ExplainPreScanNode(PlanState *planstate, Bitmapset **rels_used);
 static void ExplainNode(PlanState *planstate, List *ancestors,
 			const char *relationship, const char *plan_name,
-			ExplainState *es);
+			ExplainState *es, PlanState *squashstate);
 static void show_plan_tlist(PlanState *planstate, List *ancestors,
 				ExplainState *es);
 static void show_expression(Node *node, const char *qlabel,
@@ -579,7 +579,7 @@ ExplainPrintPlan(ExplainState *es, QueryDesc *queryDesc)
 	es->rtable_names = select_rtable_names_for_explain(es->rtable, rels_used);
 	es->deparse_cxt = deparse_context_for_plan_rtable(es->rtable,
 													  es->rtable_names);
-	ExplainNode(queryDesc->planstate, NIL, NULL, NULL, es);
+	ExplainNode(queryDesc->planstate, NIL, NULL, NULL, es, NULL);
 }
 
 /*
@@ -787,7 +787,7 @@ ExplainPreScanNode(PlanState *planstate, Bitmapset **rels_used)
 static void
 ExplainNode(PlanState *planstate, List *ancestors,
 			const char *relationship, const char *plan_name,
-			ExplainState *es)
+			ExplainState *es, PlanState *squashstate)
 {
 	Plan	   *plan = planstate->plan;
 	const char *pname;			/* node type name for text output */
@@ -804,7 +804,7 @@ ExplainNode(PlanState *planstate, List *ancestors,
 		if (gather->single_copy)
 		{
 			ExplainNode(outerPlanState(planstate), ancestors, relationship,
-						plan_name, es);
+						plan_name, es, planstate);
 			return;
 		}
 	}
@@ -1571,16 +1571,18 @@ ExplainNode(PlanState *planstate, List *ancestors,
 	/* initPlan-s */
 	if (planstate->initPlan)
 		ExplainSubPlans(planstate->initPlan, ancestors, "InitPlan", es);
+	if (squashstate != NULL && squashstate->initPlan)
+		ExplainSubPlans(squashstate->initPlan, ancestors, "SQUASHInitPlan", es);
 
 	/* lefttree */
 	if (outerPlanState(planstate))
 		ExplainNode(outerPlanState(planstate), ancestors,
-					"Outer", NULL, es);
+					"Outer", NULL, es, NULL);
 
 	/* righttree */
 	if (innerPlanState(planstate))
 		ExplainNode(innerPlanState(planstate), ancestors,
-					"Inner", NULL, es);
+					"Inner", NULL, es, NULL);
 
 	/* special child plans */
 	switch (nodeTag(plan))
@@ -1612,7 +1614,7 @@ ExplainNode(PlanState *planstate, List *ancestors,
 			break;
 		case T_SubqueryScan:
 			ExplainNode(((SubqueryScanState *) planstate)->subplan, ancestors,
-						"Subquery", NULL, es);
+						"Subquery", NULL, es, NULL);
 			break;
 		case T_CustomScan:
 			ExplainCustomChildren((CustomScanState *) planstate,
@@ -1625,6 +1627,11 @@ ExplainNode(PlanState *planstate, List *ancestors,
 	/* subPlan-s */
 	if (planstate->subPlan)
 		ExplainSubPlans(planstate->subPlan, ancestors, "SubPlan", es);
+	if (squashstate != NULL && squashstate->subPlan)
+	{
+		List *myancestors = lcons(squashstate, ancestors);
+		ExplainSubPlans(squashstate->subPlan, myancestors, "SQUASHSubPlan", es);
+	}
 
 	/* end of child plans */
 	if (haschildren)
@@ -2628,7 +2635,7 @@ ExplainMemberNodes(List *plans, PlanState **planstates,
 
 	for (j = 0; j < nplans; j++)
 		ExplainNode(planstates[j], ancestors,
-					"Member", NULL, es);
+					"Member", NULL, es, NULL);
 }
 
 /*
@@ -2649,7 +2656,7 @@ ExplainSubPlans(List *plans, List *ancestors,
 		SubPlan    *sp = (SubPlan *) sps->xprstate.expr;
 
 		ExplainNode(sps->planstate, ancestors,
-					relationship, sp->plan_name, es);
+					relationship, sp->plan_name, es, NULL);
 	}
 }
 
@@ -2664,7 +2671,8 @@ ExplainCustomChildren(CustomScanState *css, List *ancestors, ExplainState *es)
 	(list_length(css->custom_ps) != 1 ? "children" : "child");
 
 	foreach(cell, css->custom_ps)
-		ExplainNode((PlanState *) lfirst(cell), ancestors, label, NULL, es);
+		ExplainNode((PlanState *) lfirst(cell), ancestors, label, NULL, es,
+					NULL);
 }
 
 /*
diff --git a/src/backend/optimizer/plan/planner.c b/src/backend/optimizer/plan/planner.c
index 34ce39c56a..fde0c6d141 100644
--- a/src/backend/optimizer/plan/planner.c
+++ b/src/backend/optimizer/plan/planner.c
@@ -1888,12 +1888,17 @@ grouping_planner(PlannerInfo *root, double tuple_fraction)
 			 * results.
 			 */
 			bool		need_sort_for_grouping = false;
+			Plan	   *checkplan;
+			bool		insert_gather = false;
 
 			/* Try to run it in a worker. */
 			if (best_path->parallel_safe)
+			{
+				insert_gather = true;
 				best_path = (Path *)
 					create_single_copy_gather_path(root, final_rel,
 												   best_path, NULL);
+			}
 
 			current_pathkeys = best_path->pathkeys;
 
@@ -1912,6 +1917,14 @@ grouping_planner(PlannerInfo *root, double tuple_fraction)
 
 			result_plan = create_plan(root, best_path);
 
+			checkplan = result_plan;
+			if (insert_gather)
+			{
+				Assert(IsA(checkplan, Gather));
+				checkplan = outerPlan(checkplan);
+				Assert(!IsA(checkplan, Gather));
+			}
+
 			/*
 			 * create_plan returns a plan with just a "flat" tlist of required
 			 * Vars.  Usually we need to insert the sub_tlist as the tlist of
@@ -1926,7 +1939,7 @@ grouping_planner(PlannerInfo *root, double tuple_fraction)
 				 * we need, we must insert a Result node to project the
 				 * desired tlist.
 				 */
-				if (!is_projection_capable_plan(result_plan) &&
+				if (!is_projection_capable_plan(checkplan) &&
 					!tlist_same_exprs(sub_tlist, result_plan->targetlist))
 				{
 					result_plan = (Plan *) make_result(root,