Remove no-longer-used parameter for create_groupingsets_path().

numGroups is unused since commit b5635948a; let's get rid of it.

XueJing Zhao, reviewed by Richard Guo

Discussion: https://postgr.es/m/DM6PR05MB64923CC8B63A2CAF3B2E5D47B7AD9@DM6PR05MB6492.namprd05.prod.outlook.com

src/backend/optimizer/plan/planner.c

@@ -3900,8 +3900,7 @@ consider_groupingsets_paths(PlannerInfo *root,
 										  (List *) parse->havingQual,
 										  strat,
 										  new_rollups,
-										  agg_costs,
-										  dNumGroups));
+										  agg_costs));
 		return;
 	}
 
@@ -4059,8 +4058,7 @@ consider_groupingsets_paths(PlannerInfo *root,
 											  (List *) parse->havingQual,
 											  AGG_MIXED,
 											  rollups,
-											  agg_costs,
-											  dNumGroups));
+											  agg_costs));
 		}
 	}
 
@@ -4075,8 +4073,7 @@ consider_groupingsets_paths(PlannerInfo *root,
 										  (List *) parse->havingQual,
 										  AGG_SORTED,
 										  gd->rollups,
-										  agg_costs,
-										  dNumGroups));
+										  agg_costs));
 }
 
 /*

src/backend/optimizer/util/pathnode.c

@@ -3158,7 +3158,6 @@ create_agg_path(PlannerInfo *root,
  * 'having_qual' is the HAVING quals if any
  * 'rollups' is a list of RollupData nodes
  * 'agg_costs' contains cost info about the aggregate functions to be computed
- * 'numGroups' is the estimated total number of groups
  */
 GroupingSetsPath *
 create_groupingsets_path(PlannerInfo *root,
@@ -3167,8 +3166,7 @@ create_groupingsets_path(PlannerInfo *root,
 						 List *having_qual,
 						 AggStrategy aggstrategy,
 						 List *rollups,
-						 const AggClauseCosts *agg_costs,
-						 double numGroups)
+						 const AggClauseCosts *agg_costs)
 {
 	GroupingSetsPath *pathnode = makeNode(GroupingSetsPath);
 	PathTarget *target = rel->reltarget;

src/include/optimizer/pathnode.h

@@ -233,8 +233,7 @@ extern GroupingSetsPath *create_groupingsets_path(PlannerInfo *root,
 												  List *having_qual,
 												  AggStrategy aggstrategy,
 												  List *rollups,
-												  const AggClauseCosts *agg_costs,
-												  double numGroups);
+												  const AggClauseCosts *agg_costs);
 extern MinMaxAggPath *create_minmaxagg_path(PlannerInfo *root,
 											RelOptInfo *rel,
 											PathTarget *target,