diff --git a/src/backend/nodes/outfuncs.c b/src/backend/nodes/outfuncs.c
index e32b92e299..a35160a81c 100644
--- a/src/backend/nodes/outfuncs.c
+++ b/src/backend/nodes/outfuncs.c
@@ -2385,6 +2385,7 @@ _outRelOptInfo(StringInfo str, const RelOptInfo *node)
 	WRITE_BOOL_FIELD(consider_partitionwise_join);
 	WRITE_BITMAPSET_FIELD(top_parent_relids);
 	WRITE_BOOL_FIELD(partbounds_merged);
+	WRITE_BITMAPSET_FIELD(live_parts);
 	WRITE_BITMAPSET_FIELD(all_partrels);
 }
 
diff --git a/src/backend/optimizer/path/joinrels.c b/src/backend/optimizer/path/joinrels.c
index 0dbe2ac726..8b69870cf4 100644
--- a/src/backend/optimizer/path/joinrels.c
+++ b/src/backend/optimizer/path/joinrels.c
@@ -1539,6 +1539,7 @@ try_partitionwise_join(PlannerInfo *root, RelOptInfo *rel1, RelOptInfo *rel2,
 												 child_sjinfo,
 												 child_sjinfo->jointype);
 			joinrel->part_rels[cnt_parts] = child_joinrel;
+			joinrel->live_parts = bms_add_member(joinrel->live_parts, cnt_parts);
 			joinrel->all_partrels = bms_add_members(joinrel->all_partrels,
 													child_joinrel->relids);
 		}
diff --git a/src/backend/optimizer/plan/planner.c b/src/backend/optimizer/plan/planner.c
index 1868c4eff4..2a0dee9b5b 100644
--- a/src/backend/optimizer/plan/planner.c
+++ b/src/backend/optimizer/plan/planner.c
@@ -6989,19 +6989,22 @@ apply_scanjoin_target_to_paths(PlannerInfo *root,
 	if (rel_is_partitioned)
 	{
 		List	   *live_children = NIL;
-		int			partition_idx;
+		int			i;
 
 		/* Adjust each partition. */
-		for (partition_idx = 0; partition_idx < rel->nparts; partition_idx++)
+		i = -1;
+		while ((i = bms_next_member(rel->live_parts, i)) >= 0)
 		{
-			RelOptInfo *child_rel = rel->part_rels[partition_idx];
+			RelOptInfo *child_rel = rel->part_rels[i];
 			AppendRelInfo **appinfos;
 			int			nappinfos;
 			List	   *child_scanjoin_targets = NIL;
 			ListCell   *lc;
 
-			/* Pruned or dummy children can be ignored. */
-			if (child_rel == NULL || IS_DUMMY_REL(child_rel))
+			Assert(child_rel != NULL);
+
+			/* Dummy children can be ignored. */
+			if (IS_DUMMY_REL(child_rel))
 				continue;
 
 			/* Translate scan/join targets for this child. */
@@ -7082,32 +7085,35 @@ create_partitionwise_grouping_paths(PlannerInfo *root,
 									PartitionwiseAggregateType patype,
 									GroupPathExtraData *extra)
 {
-	int			nparts = input_rel->nparts;
-	int			cnt_parts;
 	List	   *grouped_live_children = NIL;
 	List	   *partially_grouped_live_children = NIL;
 	PathTarget *target = grouped_rel->reltarget;
 	bool		partial_grouping_valid = true;
+	int			i;
 
 	Assert(patype != PARTITIONWISE_AGGREGATE_NONE);
 	Assert(patype != PARTITIONWISE_AGGREGATE_PARTIAL ||
 		   partially_grouped_rel != NULL);
 
 	/* Add paths for partitionwise aggregation/grouping. */
-	for (cnt_parts = 0; cnt_parts < nparts; cnt_parts++)
+	i = -1;
+	while ((i = bms_next_member(input_rel->live_parts, i)) >= 0)
 	{
-		RelOptInfo *child_input_rel = input_rel->part_rels[cnt_parts];
-		PathTarget *child_target = copy_pathtarget(target);
+		RelOptInfo *child_input_rel = input_rel->part_rels[i];
+		PathTarget *child_target;
 		AppendRelInfo **appinfos;
 		int			nappinfos;
 		GroupPathExtraData child_extra;
 		RelOptInfo *child_grouped_rel;
 		RelOptInfo *child_partially_grouped_rel;
 
-		/* Pruned or dummy children can be ignored. */
-		if (child_input_rel == NULL || IS_DUMMY_REL(child_input_rel))
+		Assert(child_input_rel != NULL);
+
+		/* Dummy children can be ignored. */
+		if (IS_DUMMY_REL(child_input_rel))
 			continue;
 
+		child_target = copy_pathtarget(target);
 		/*
 		 * Copy the given "extra" structure as is and then override the
 		 * members specific to this child.
diff --git a/src/backend/optimizer/util/inherit.c b/src/backend/optimizer/util/inherit.c
index 992ef87b9d..c758172efa 100644
--- a/src/backend/optimizer/util/inherit.c
+++ b/src/backend/optimizer/util/inherit.c
@@ -348,7 +348,7 @@ expand_partitioned_rtentry(PlannerInfo *root, RelOptInfo *relinfo,
 	 * that survive pruning.  Below, we will initialize child objects for the
 	 * surviving partitions.
 	 */
-	live_parts = prune_append_rel_partitions(relinfo);
+	relinfo->live_parts = live_parts = prune_append_rel_partitions(relinfo);
 
 	/* Expand simple_rel_array and friends to hold child objects. */
 	num_live_parts = bms_num_members(live_parts);
diff --git a/src/backend/optimizer/util/relnode.c b/src/backend/optimizer/util/relnode.c
index e105a4d5f1..47769cea45 100644
--- a/src/backend/optimizer/util/relnode.c
+++ b/src/backend/optimizer/util/relnode.c
@@ -255,6 +255,7 @@ build_simple_rel(PlannerInfo *root, int relid, RelOptInfo *parent)
 	rel->partbounds_merged = false;
 	rel->partition_qual = NIL;
 	rel->part_rels = NULL;
+	rel->live_parts = NULL;
 	rel->all_partrels = NULL;
 	rel->partexprs = NULL;
 	rel->nullable_partexprs = NULL;
@@ -669,6 +670,7 @@ build_join_rel(PlannerInfo *root,
 	joinrel->partbounds_merged = false;
 	joinrel->partition_qual = NIL;
 	joinrel->part_rels = NULL;
+	joinrel->live_parts = NULL;
 	joinrel->all_partrels = NULL;
 	joinrel->partexprs = NULL;
 	joinrel->nullable_partexprs = NULL;
@@ -847,6 +849,7 @@ build_child_join_rel(PlannerInfo *root, RelOptInfo *outer_rel,
 	joinrel->partbounds_merged = false;
 	joinrel->partition_qual = NIL;
 	joinrel->part_rels = NULL;
+	joinrel->live_parts = NULL;
 	joinrel->all_partrels = NULL;
 	joinrel->partexprs = NULL;
 	joinrel->nullable_partexprs = NULL;
diff --git a/src/backend/partitioning/partprune.c b/src/backend/partitioning/partprune.c
index c79374265c..e00edbe5c8 100644
--- a/src/backend/partitioning/partprune.c
+++ b/src/backend/partitioning/partprune.c
@@ -654,15 +654,14 @@ make_partitionedrel_pruneinfo(PlannerInfo *root, RelOptInfo *parentrel,
 		relid_map = (Oid *) palloc0(nparts * sizeof(Oid));
 		present_parts = NULL;
 
-		for (i = 0; i < nparts; i++)
+		i = -1;
+		while ((i = bms_next_member(subpart->live_parts, i)) >= 0)
 		{
 			RelOptInfo *partrel = subpart->part_rels[i];
 			int			subplanidx;
 			int			subpartidx;
 
-			/* Skip processing pruned partitions. */
-			if (partrel == NULL)
-				continue;
+			Assert(partrel != NULL);
 
 			subplan_map[i] = subplanidx = relid_subplan_map[partrel->relid] - 1;
 			subpart_map[i] = subpartidx = relid_subpart_map[partrel->relid] - 1;
diff --git a/src/include/nodes/pathnodes.h b/src/include/nodes/pathnodes.h
index b7b2817a5d..ff6a641b6e 100644
--- a/src/include/nodes/pathnodes.h
+++ b/src/include/nodes/pathnodes.h
@@ -762,6 +762,9 @@ typedef struct RelOptInfo
 	List	   *partition_qual; /* Partition constraint, if not the root */
 	struct RelOptInfo **part_rels;	/* Array of RelOptInfos of partitions,
 									 * stored in the same order as bounds */
+	Bitmapset  *live_parts;		/* Bitmap with members to indicate which
+								 * elements of the 'part_rels' array are
+								 * filled */
 	Relids		all_partrels;	/* Relids set of all partition relids */
 	List	  **partexprs;		/* Non-nullable partition key expressions */
 	List	  **nullable_partexprs; /* Nullable partition key expressions */