Fix run-time partition pruning for appends with multiple source rels.

The previous coding here supposed that if run-time partitioning applied to
a particular Append/MergeAppend plan, then all child plans of that node
must be members of a single partitioning hierarchy.  This is totally wrong,
since an Append could be formed from a UNION ALL: we could have multiple
hierarchies sharing the same Append, or child plans that aren't part of any
hierarchy.

To fix, restructure the related plan-time and execution-time data
structures so that we can have a separate list or array for each
partitioning hierarchy.  Also track subplans that are not part of any
hierarchy, and make sure they don't get pruned.

Per reports from Phil Florent and others.  Back-patch to v11, since
the bug originated there.

David Rowley, with a lot of cosmetic adjustments by me; thanks also
to Amit Langote for review.

Discussion: https://postgr.es/m/HE1PR03MB17068BB27404C90B5B788BCABA7B0@HE1PR03MB1706.eurprd03.prod.outlook.com

10 files changed, 523 insertions, 242 deletions

diff --git a/src/backend/executor/execPartition.c b/src/backend/executor/execPartition.c
index 11b7e67e4d6..d13be4145f8 100644
--- a/src/backend/executor/execPartition.c
+++ b/src/backend/executor/execPartition.c
@@ -48,8 +48,8 @@ static char *ExecBuildSlotPartitionKeyDescription(Relation rel,
 									 bool *isnull,
 									 int maxfieldlen);
 static List *adjust_partition_tlist(List *tlist, TupleConversionMap *map);
-static void find_matching_subplans_recurse(PartitionPruneState *prunestate,
-							   PartitionPruningData *pprune,
+static void find_matching_subplans_recurse(PartitionPruningData *prunedata,
+							   PartitionedRelPruningData *pprune,
 							   bool initial_prune,
 							   Bitmapset **validsubplans);
 
@@ -1417,34 +1417,42 @@ adjust_partition_tlist(List *tlist, TupleConversionMap *map)
  *
  * 'planstate' is the parent plan node's execution state.
  *
- * 'partitionpruneinfo' is a List of PartitionPruneInfos as generated by
+ * 'partitionpruneinfo' is a PartitionPruneInfo as generated by
  * make_partition_pruneinfo.  Here we build a PartitionPruneState containing a
- * PartitionPruningData for each item in that List.  This data can be re-used
- * each time we re-evaluate which partitions match the pruning steps provided
- * in each PartitionPruneInfo.
+ * PartitionPruningData for each partitioning hierarchy (i.e., each sublist of
+ * partitionpruneinfo->prune_infos), each of which contains a
+ * PartitionedRelPruningData for each PartitionedRelPruneInfo appearing in
+ * that sublist.  This two-level system is needed to keep from confusing the
+ * different hierarchies when a UNION ALL contains multiple partitioned tables
+ * as children.  The data stored in each PartitionedRelPruningData can be
+ * re-used each time we re-evaluate which partitions match the pruning steps
+ * provided in each PartitionedRelPruneInfo.
  */
 PartitionPruneState *
-ExecCreatePartitionPruneState(PlanState *planstate, List *partitionpruneinfo)
+ExecCreatePartitionPruneState(PlanState *planstate,
+							  PartitionPruneInfo *partitionpruneinfo)
 {
 	PartitionPruneState *prunestate;
-	PartitionPruningData *prunedata;
+	int			n_part_hierarchies;
 	ListCell   *lc;
 	int			i;
 
-	Assert(partitionpruneinfo != NIL);
+	n_part_hierarchies = list_length(partitionpruneinfo->prune_infos);
+	Assert(n_part_hierarchies > 0);
 
 	/*
 	 * Allocate the data structure
 	 */
-	prunestate = (PartitionPruneState *) palloc(sizeof(PartitionPruneState));
-	prunedata = (PartitionPruningData *)
-		palloc(sizeof(PartitionPruningData) * list_length(partitionpruneinfo));
+	prunestate = (PartitionPruneState *)
+		palloc(offsetof(PartitionPruneState, partprunedata) +
+			   sizeof(PartitionPruningData *) * n_part_hierarchies);
 
-	prunestate->partprunedata = prunedata;
-	prunestate->num_partprunedata = list_length(partitionpruneinfo);
+	prunestate->execparamids = NULL;
+	/* other_subplans can change at runtime, so we need our own copy */
+	prunestate->other_subplans = bms_copy(partitionpruneinfo->other_subplans);
 	prunestate->do_initial_prune = false;	/* may be set below */
 	prunestate->do_exec_prune = false;	/* may be set below */
-	prunestate->execparamids = NULL;
+	prunestate->num_partprunedata = n_part_hierarchies;
 
 	/*
 	 * Create a short-term memory context which we'll use when making calls to
@@ -1458,110 +1466,128 @@ ExecCreatePartitionPruneState(PlanState *planstate, List *partitionpruneinfo)
 							  ALLOCSET_DEFAULT_SIZES);
 
 	i = 0;
-	foreach(lc, partitionpruneinfo)
+	foreach(lc, partitionpruneinfo->prune_infos)
 	{
-		PartitionPruneInfo *pinfo = castNode(PartitionPruneInfo, lfirst(lc));
-		PartitionPruningData *pprune = &prunedata[i];
-		PartitionPruneContext *context = &pprune->context;
-		PartitionDesc partdesc;
-		PartitionKey partkey;
-		int			partnatts;
-		int			n_steps;
+		List	   *partrelpruneinfos = lfirst_node(List, lc);
+		int			npartrelpruneinfos = list_length(partrelpruneinfos);
+		PartitionPruningData *prunedata;
 		ListCell   *lc2;
+		int			j;
 
-		/*
-		 * We must copy the subplan_map rather than pointing directly to the
-		 * plan's version, as we may end up making modifications to it later.
-		 */
-		pprune->subplan_map = palloc(sizeof(int) * pinfo->nparts);
-		memcpy(pprune->subplan_map, pinfo->subplan_map,
-			   sizeof(int) * pinfo->nparts);
+		prunedata = (PartitionPruningData *)
+			palloc(offsetof(PartitionPruningData, partrelprunedata) +
+				   npartrelpruneinfos * sizeof(PartitionedRelPruningData));
+		prunestate->partprunedata[i] = prunedata;
+		prunedata->num_partrelprunedata = npartrelpruneinfos;
 
-		/* We can use the subpart_map verbatim, since we never modify it */
-		pprune->subpart_map = pinfo->subpart_map;
-
-		/* present_parts is also subject to later modification */
-		pprune->present_parts = bms_copy(pinfo->present_parts);
-
-		/*
-		 * We need to hold a pin on the partitioned table's relcache entry so
-		 * that we can rely on its copies of the table's partition key and
-		 * partition descriptor.  We need not get a lock though; one should
-		 * have been acquired already by InitPlan or
-		 * ExecLockNonLeafAppendTables.
-		 */
-		context->partrel = relation_open(pinfo->reloid, NoLock);
-
-		partkey = RelationGetPartitionKey(context->partrel);
-		partdesc = RelationGetPartitionDesc(context->partrel);
-		n_steps = list_length(pinfo->pruning_steps);
-
-		context->strategy = partkey->strategy;
-		context->partnatts = partnatts = partkey->partnatts;
-		context->nparts = pinfo->nparts;
-		context->boundinfo = partdesc->boundinfo;
-		context->partcollation = partkey->partcollation;
-		context->partsupfunc = partkey->partsupfunc;
-
-		/* We'll look up type-specific support functions as needed */
-		context->stepcmpfuncs = (FmgrInfo *)
-			palloc0(sizeof(FmgrInfo) * n_steps * partnatts);
-
-		context->ppccontext = CurrentMemoryContext;
-		context->planstate = planstate;
-
-		/* Initialize expression state for each expression we need */
-		context->exprstates = (ExprState **)
-			palloc0(sizeof(ExprState *) * n_steps * partnatts);
-		foreach(lc2, pinfo->pruning_steps)
+		j = 0;
+		foreach(lc2, partrelpruneinfos)
 		{
-			PartitionPruneStepOp *step = (PartitionPruneStepOp *) lfirst(lc2);
+			PartitionedRelPruneInfo *pinfo = lfirst_node(PartitionedRelPruneInfo, lc2);
+			PartitionedRelPruningData *pprune = &prunedata->partrelprunedata[j];
+			PartitionPruneContext *context = &pprune->context;
+			PartitionDesc partdesc;
+			PartitionKey partkey;
+			int			partnatts;
+			int			n_steps;
 			ListCell   *lc3;
-			int			keyno;
 
-			/* not needed for other step kinds */
-			if (!IsA(step, PartitionPruneStepOp))
-				continue;
+			/*
+			 * We must copy the subplan_map rather than pointing directly to
+			 * the plan's version, as we may end up making modifications to it
+			 * later.
+			 */
+			pprune->subplan_map = palloc(sizeof(int) * pinfo->nparts);
+			memcpy(pprune->subplan_map, pinfo->subplan_map,
+				   sizeof(int) * pinfo->nparts);
 
-			Assert(list_length(step->exprs) <= partnatts);
+			/* We can use the subpart_map verbatim, since we never modify it */
+			pprune->subpart_map = pinfo->subpart_map;
 
-			keyno = 0;
-			foreach(lc3, step->exprs)
+			/* present_parts is also subject to later modification */
+			pprune->present_parts = bms_copy(pinfo->present_parts);
+
+			/*
+			 * We need to hold a pin on the partitioned table's relcache entry
+			 * so that we can rely on its copies of the table's partition key
+			 * and partition descriptor.  We need not get a lock though; one
+			 * should have been acquired already by InitPlan or
+			 * ExecLockNonLeafAppendTables.
+			 */
+			context->partrel = relation_open(pinfo->reloid, NoLock);
+
+			partkey = RelationGetPartitionKey(context->partrel);
+			partdesc = RelationGetPartitionDesc(context->partrel);
+			n_steps = list_length(pinfo->pruning_steps);
+
+			context->strategy = partkey->strategy;
+			context->partnatts = partnatts = partkey->partnatts;
+			context->nparts = pinfo->nparts;
+			context->boundinfo = partdesc->boundinfo;
+			context->partcollation = partkey->partcollation;
+			context->partsupfunc = partkey->partsupfunc;
+
+			/* We'll look up type-specific support functions as needed */
+			context->stepcmpfuncs = (FmgrInfo *)
+				palloc0(sizeof(FmgrInfo) * n_steps * partnatts);
+
+			context->ppccontext = CurrentMemoryContext;
+			context->planstate = planstate;
+
+			/* Initialize expression state for each expression we need */
+			context->exprstates = (ExprState **)
+				palloc0(sizeof(ExprState *) * n_steps * partnatts);
+			foreach(lc3, pinfo->pruning_steps)
 			{
-				Expr	   *expr = (Expr *) lfirst(lc3);
+				PartitionPruneStepOp *step = (PartitionPruneStepOp *) lfirst(lc3);
+				ListCell   *lc4;
+				int			keyno;
+
+				/* not needed for other step kinds */
+				if (!IsA(step, PartitionPruneStepOp))
+					continue;
 
-				/* not needed for Consts */
-				if (!IsA(expr, Const))
+				Assert(list_length(step->exprs) <= partnatts);
+
+				keyno = 0;
+				foreach(lc4, step->exprs)
 				{
-					int			stateidx = PruneCxtStateIdx(partnatts,
-															step->step.step_id,
-															keyno);
+					Expr	   *expr = (Expr *) lfirst(lc4);
+
+					/* not needed for Consts */
+					if (!IsA(expr, Const))
+					{
+						int			stateidx = PruneCxtStateIdx(partnatts,
+																step->step.step_id,
+																keyno);
 
-					context->exprstates[stateidx] =
-						ExecInitExpr(expr, context->planstate);
+						context->exprstates[stateidx] =
+							ExecInitExpr(expr, context->planstate);
+					}
+					keyno++;
 				}
-				keyno++;
 			}
-		}
 
-		/* Array is not modified at runtime, so just point to plan's copy */
-		context->exprhasexecparam = pinfo->hasexecparam;
+			/* Array is not modified at runtime, so just point to plan's copy */
+			context->exprhasexecparam = pinfo->hasexecparam;
 
-		pprune->pruning_steps = pinfo->pruning_steps;
-		pprune->do_initial_prune = pinfo->do_initial_prune;
-		pprune->do_exec_prune = pinfo->do_exec_prune;
+			pprune->pruning_steps = pinfo->pruning_steps;
+			pprune->do_initial_prune = pinfo->do_initial_prune;
+			pprune->do_exec_prune = pinfo->do_exec_prune;
 
-		/* Record if pruning would be useful at any level */
-		prunestate->do_initial_prune |= pinfo->do_initial_prune;
-		prunestate->do_exec_prune |= pinfo->do_exec_prune;
+			/* Record if pruning would be useful at any level */
+			prunestate->do_initial_prune |= pinfo->do_initial_prune;
+			prunestate->do_exec_prune |= pinfo->do_exec_prune;
 
-		/*
-		 * Accumulate the IDs of all PARAM_EXEC Params affecting the
-		 * partitioning decisions at this plan node.
-		 */
-		prunestate->execparamids = bms_add_members(prunestate->execparamids,
-												   pinfo->execparamids);
+			/*
+			 * Accumulate the IDs of all PARAM_EXEC Params affecting the
+			 * partitioning decisions at this plan node.
+			 */
+			prunestate->execparamids = bms_add_members(prunestate->execparamids,
+													   pinfo->execparamids);
 
+			j++;
+		}
 		i++;
 	}
 
@@ -1578,13 +1604,17 @@ ExecCreatePartitionPruneState(PlanState *planstate, List *partitionpruneinfo)
 void
 ExecDestroyPartitionPruneState(PartitionPruneState *prunestate)
 {
+	PartitionPruningData **partprunedata = prunestate->partprunedata;
 	int			i;
 
 	for (i = 0; i < prunestate->num_partprunedata; i++)
 	{
-		PartitionPruningData *pprune = &prunestate->partprunedata[i];
+		PartitionPruningData *prunedata = partprunedata[i];
+		PartitionedRelPruningData *pprune = prunedata->partrelprunedata;
+		int			j;
 
-		relation_close(pprune->context.partrel, NoLock);
+		for (j = 0; j < prunedata->num_partrelprunedata; j++)
+			relation_close(pprune[j].context.partrel, NoLock);
 	}
 }
 
@@ -1604,31 +1634,46 @@ ExecDestroyPartitionPruneState(PartitionPruneState *prunestate)
 Bitmapset *
 ExecFindInitialMatchingSubPlans(PartitionPruneState *prunestate, int nsubplans)
 {
-	PartitionPruningData *pprune;
-	MemoryContext oldcontext;
 	Bitmapset  *result = NULL;
+	MemoryContext oldcontext;
+	int			i;
 
 	Assert(prunestate->do_initial_prune);
 
-	pprune = prunestate->partprunedata;
-
 	/*
 	 * Switch to a temp context to avoid leaking memory in the executor's
 	 * memory context.
 	 */
 	oldcontext = MemoryContextSwitchTo(prunestate->prune_context);
 
-	/* Perform pruning without using PARAM_EXEC Params */
-	find_matching_subplans_recurse(prunestate, pprune, true, &result);
+	/*
+	 * For each hierarchy, do the pruning tests, and add deletable subplans'
+	 * indexes to "result".
+	 */
+	for (i = 0; i < prunestate->num_partprunedata; i++)
+	{
+		PartitionPruningData *prunedata;
+		PartitionedRelPruningData *pprune;
+
+		prunedata = prunestate->partprunedata[i];
+		pprune = &prunedata->partrelprunedata[0];
+
+		/* Perform pruning without using PARAM_EXEC Params */
+		find_matching_subplans_recurse(prunedata, pprune, true, &result);
+
+		/* Expression eval may have used space in node's ps_ExprContext too */
+		ResetExprContext(pprune->context.planstate->ps_ExprContext);
+	}
 
 	MemoryContextSwitchTo(oldcontext);
 
 	/* Copy result out of the temp context before we reset it */
 	result = bms_copy(result);
 
+	/* Add in any subplans that partition pruning didn't account for */
+	result = bms_add_members(result, prunestate->other_subplans);
+
 	MemoryContextReset(prunestate->prune_context);
-	/* Expression eval may have used space in node's ps_ExprContext too */
-	ResetExprContext(pprune->context.planstate->ps_ExprContext);
 
 	/*
 	 * If any subplans were pruned, we must re-sequence the subplan indexes so
@@ -1638,14 +1683,17 @@ ExecFindInitialMatchingSubPlans(PartitionPruneState *prunestate, int nsubplans)
 	if (bms_num_members(result) < nsubplans)
 	{
 		int		   *new_subplan_indexes;
+		Bitmapset  *new_other_subplans;
 		int			i;
 		int			newidx;
 
 		/*
 		 * First we must build a temporary array which maps old subplan
-		 * indexes to new ones.
+		 * indexes to new ones.  While we're at it, also recompute the
+		 * other_subplans set, since indexes in it may change.
 		 */
 		new_subplan_indexes = (int *) palloc(sizeof(int) * nsubplans);
+		new_other_subplans = NULL;
 		newidx = 0;
 		for (i = 0; i < nsubplans; i++)
 		{
@@ -1653,58 +1701,74 @@ ExecFindInitialMatchingSubPlans(PartitionPruneState *prunestate, int nsubplans)
 				new_subplan_indexes[i] = newidx++;
 			else
 				new_subplan_indexes[i] = -1;	/* Newly pruned */
+
+			if (bms_is_member(i, prunestate->other_subplans))
+				new_other_subplans = bms_add_member(new_other_subplans,
+													new_subplan_indexes[i]);
 		}
+		bms_free(prunestate->other_subplans);
+		prunestate->other_subplans = new_other_subplans;
 
 		/*
-		 * Now we can update each PartitionPruneInfo's subplan_map with new
-		 * subplan indexes.  We must also recompute its present_parts bitmap.
-		 * We perform this loop in back-to-front order so that we determine
-		 * present_parts for the lowest-level partitioned tables first.  This
-		 * way we can tell whether a sub-partitioned table's partitions were
-		 * entirely pruned so we can exclude that from 'present_parts'.
+		 * Now we can update each PartitionedRelPruneInfo's subplan_map with
+		 * new subplan indexes.  We must also recompute its present_parts
+		 * bitmap.
 		 */
-		for (i = prunestate->num_partprunedata - 1; i >= 0; i--)
+		for (i = 0; i < prunestate->num_partprunedata; i++)
 		{
-			int			nparts;
+			PartitionPruningData *prunedata = prunestate->partprunedata[i];
 			int			j;
 
-			pprune = &prunestate->partprunedata[i];
-			nparts = pprune->context.nparts;
-			/* We just rebuild present_parts from scratch */
-			bms_free(pprune->present_parts);
-			pprune->present_parts = NULL;
-
-			for (j = 0; j < nparts; j++)
+			/*
+			 * Within each hierarchy, we perform this loop in back-to-front
+			 * order so that we determine present_parts for the lowest-level
+			 * partitioned tables first.  This way we can tell whether a
+			 * sub-partitioned table's partitions were entirely pruned so we
+			 * can exclude that from 'present_parts'.
+			 */
+			for (j = prunedata->num_partrelprunedata - 1; j >= 0; j--)
 			{
-				int			oldidx = pprune->subplan_map[j];
-				int			subidx;
+				PartitionedRelPruningData *pprune = &prunedata->partrelprunedata[j];
+				int			nparts = pprune->context.nparts;
+				int			k;
 
-				/*
-				 * If this partition existed as a subplan then change the old
-				 * subplan index to the new subplan index.  The new index may
-				 * become -1 if the partition was pruned above, or it may just
-				 * come earlier in the subplan list due to some subplans being
-				 * removed earlier in the list.  If it's a subpartition, add
-				 * it to present_parts unless it's entirely pruned.
-				 */
-				if (oldidx >= 0)
-				{
-					Assert(oldidx < nsubplans);
-					pprune->subplan_map[j] = new_subplan_indexes[oldidx];
+				/* We just rebuild present_parts from scratch */
+				bms_free(pprune->present_parts);
+				pprune->present_parts = NULL;
 
-					if (new_subplan_indexes[oldidx] >= 0)
-						pprune->present_parts =
-							bms_add_member(pprune->present_parts, j);
-				}
-				else if ((subidx = pprune->subpart_map[j]) >= 0)
+				for (k = 0; k < nparts; k++)
 				{
-					PartitionPruningData *subprune;
+					int			oldidx = pprune->subplan_map[k];
+					int			subidx;
 
-					subprune = &prunestate->partprunedata[subidx];
+					/*
+					 * If this partition existed as a subplan then change the
+					 * old subplan index to the new subplan index.  The new
+					 * index may become -1 if the partition was pruned above,
+					 * or it may just come earlier in the subplan list due to
+					 * some subplans being removed earlier in the list.  If
+					 * it's a subpartition, add it to present_parts unless
+					 * it's entirely pruned.
+					 */
+					if (oldidx >= 0)
+					{
+						Assert(oldidx < nsubplans);
+						pprune->subplan_map[k] = new_subplan_indexes[oldidx];
 
-					if (!bms_is_empty(subprune->present_parts))
-						pprune->present_parts =
-							bms_add_member(pprune->present_parts, j);
+						if (new_subplan_indexes[oldidx] >= 0)
+							pprune->present_parts =
+								bms_add_member(pprune->present_parts, k);
+					}
+					else if ((subidx = pprune->subpart_map[k]) >= 0)
+					{
+						PartitionedRelPruningData *subprune;
+
+						subprune = &prunedata->partrelprunedata[subidx];
+
+						if (!bms_is_empty(subprune->present_parts))
+							pprune->present_parts =
+								bms_add_member(pprune->present_parts, k);
+					}
 				}
 			}
 		}
@@ -1725,11 +1789,9 @@ ExecFindInitialMatchingSubPlans(PartitionPruneState *prunestate, int nsubplans)
 Bitmapset *
 ExecFindMatchingSubPlans(PartitionPruneState *prunestate)
 {
-	PartitionPruningData *pprune;
-	MemoryContext oldcontext;
 	Bitmapset  *result = NULL;
-
-	pprune = prunestate->partprunedata;
+	MemoryContext oldcontext;
+	int			i;
 
 	/*
 	 * Switch to a temp context to avoid leaking memory in the executor's
@@ -1737,16 +1799,33 @@ ExecFindMatchingSubPlans(PartitionPruneState *prunestate)
 	 */
 	oldcontext = MemoryContextSwitchTo(prunestate->prune_context);
 
-	find_matching_subplans_recurse(prunestate, pprune, false, &result);
+	/*
+	 * For each hierarchy, do the pruning tests, and add deletable subplans'
+	 * indexes to "result".
+	 */
+	for (i = 0; i < prunestate->num_partprunedata; i++)
+	{
+		PartitionPruningData *prunedata;
+		PartitionedRelPruningData *pprune;
+
+		prunedata = prunestate->partprunedata[i];
+		pprune = &prunedata->partrelprunedata[0];
+
+		find_matching_subplans_recurse(prunedata, pprune, false, &result);
+
+		/* Expression eval may have used space in node's ps_ExprContext too */
+		ResetExprContext(pprune->context.planstate->ps_ExprContext);
+	}
 
 	MemoryContextSwitchTo(oldcontext);
 
 	/* Copy result out of the temp context before we reset it */
 	result = bms_copy(result);
 
+	/* Add in any subplans that partition pruning didn't account for */
+	result = bms_add_members(result, prunestate->other_subplans);
+
 	MemoryContextReset(prunestate->prune_context);
-	/* Expression eval may have used space in node's ps_ExprContext too */
-	ResetExprContext(pprune->context.planstate->ps_ExprContext);
 
 	return result;
 }
@@ -1759,8 +1838,8 @@ ExecFindMatchingSubPlans(PartitionPruneState *prunestate)
  * Adds valid (non-prunable) subplan IDs to *validsubplans
  */
 static void
-find_matching_subplans_recurse(PartitionPruneState *prunestate,
-							   PartitionPruningData *pprune,
+find_matching_subplans_recurse(PartitionPruningData *prunedata,
+							   PartitionedRelPruningData *pprune,
 							   bool initial_prune,
 							   Bitmapset **validsubplans)
 {
@@ -1802,8 +1881,8 @@ find_matching_subplans_recurse(PartitionPruneState *prunestate,
 			int			partidx = pprune->subpart_map[i];
 
 			if (partidx >= 0)
-				find_matching_subplans_recurse(prunestate,
-											   &prunestate->partprunedata[partidx],
+				find_matching_subplans_recurse(prunedata,
+											   &prunedata->partrelprunedata[partidx],
 											   initial_prune, validsubplans);
 			else
 			{
diff --git a/src/backend/executor/nodeAppend.c b/src/backend/executor/nodeAppend.c
index 86a68d30201..f08dfcbcf01 100644
--- a/src/backend/executor/nodeAppend.c
+++ b/src/backend/executor/nodeAppend.c
@@ -129,7 +129,7 @@ ExecInitAppend(Append *node, EState *estate, int eflags)
 	appendstate->as_whichplan = INVALID_SUBPLAN_INDEX;
 
 	/* If run-time partition pruning is enabled, then set that up now */
-	if (node->part_prune_infos != NIL)
+	if (node->part_prune_info != NULL)
 	{
 		PartitionPruneState *prunestate;
 
@@ -138,7 +138,7 @@ ExecInitAppend(Append *node, EState *estate, int eflags)
 
 		/* Create the working data structure for pruning. */
 		prunestate = ExecCreatePartitionPruneState(&appendstate->ps,
-												   node->part_prune_infos);
+												   node->part_prune_info);
 		appendstate->as_prune_state = prunestate;
 
 		/* Perform an initial partition prune, if required. */
diff --git a/src/backend/executor/nodeMergeAppend.c b/src/backend/executor/nodeMergeAppend.c
index be43014cb89..9a72d3a0ace 100644
--- a/src/backend/executor/nodeMergeAppend.c
+++ b/src/backend/executor/nodeMergeAppend.c
@@ -90,7 +90,7 @@ ExecInitMergeAppend(MergeAppend *node, EState *estate, int eflags)
 	mergestate->ms_noopscan = false;
 
 	/* If run-time partition pruning is enabled, then set that up now */
-	if (node->part_prune_infos != NIL)
+	if (node->part_prune_info != NULL)
 	{
 		PartitionPruneState *prunestate;
 
@@ -98,7 +98,7 @@ ExecInitMergeAppend(MergeAppend *node, EState *estate, int eflags)
 		ExecAssignExprContext(estate, &mergestate->ps);
 
 		prunestate = ExecCreatePartitionPruneState(&mergestate->ps,
-												   node->part_prune_infos);
+												   node->part_prune_info);
 		mergestate->ms_prune_state = prunestate;
 
 		/* Perform an initial partition prune, if required. */
diff --git a/src/backend/nodes/copyfuncs.c b/src/backend/nodes/copyfuncs.c
index 17b650b8cb9..7c8220cf651 100644
--- a/src/backend/nodes/copyfuncs.c
+++ b/src/backend/nodes/copyfuncs.c
@@ -245,7 +245,7 @@ _copyAppend(const Append *from)
 	COPY_NODE_FIELD(appendplans);
 	COPY_SCALAR_FIELD(first_partial_plan);
 	COPY_NODE_FIELD(partitioned_rels);
-	COPY_NODE_FIELD(part_prune_infos);
+	COPY_NODE_FIELD(part_prune_info);
 
 	return newnode;
 }
@@ -273,7 +273,7 @@ _copyMergeAppend(const MergeAppend *from)
 	COPY_POINTER_FIELD(sortOperators, from->numCols * sizeof(Oid));
 	COPY_POINTER_FIELD(collations, from->numCols * sizeof(Oid));
 	COPY_POINTER_FIELD(nullsFirst, from->numCols * sizeof(bool));
-	COPY_NODE_FIELD(part_prune_infos);
+	COPY_NODE_FIELD(part_prune_info);
 
 	return newnode;
 }
@@ -1182,6 +1182,17 @@ _copyPartitionPruneInfo(const PartitionPruneInfo *from)
 {
 	PartitionPruneInfo *newnode = makeNode(PartitionPruneInfo);
 
+	COPY_NODE_FIELD(prune_infos);
+	COPY_BITMAPSET_FIELD(other_subplans);
+
+	return newnode;
+}
+
+static PartitionedRelPruneInfo *
+_copyPartitionedRelPruneInfo(const PartitionedRelPruneInfo *from)
+{
+	PartitionedRelPruneInfo *newnode = makeNode(PartitionedRelPruneInfo);
+
 	COPY_SCALAR_FIELD(reloid);
 	COPY_NODE_FIELD(pruning_steps);
 	COPY_BITMAPSET_FIELD(present_parts);
@@ -4908,6 +4919,9 @@ copyObjectImpl(const void *from)
 		case T_PartitionPruneInfo:
 			retval = _copyPartitionPruneInfo(from);
 			break;
+		case T_PartitionedRelPruneInfo:
+			retval = _copyPartitionedRelPruneInfo(from);
+			break;
 		case T_PartitionPruneStepOp:
 			retval = _copyPartitionPruneStepOp(from);
 			break;
diff --git a/src/backend/nodes/outfuncs.c b/src/backend/nodes/outfuncs.c
index a6454ce28b3..6269f474d2c 100644
--- a/src/backend/nodes/outfuncs.c
+++ b/src/backend/nodes/outfuncs.c
@@ -402,7 +402,7 @@ _outAppend(StringInfo str, const Append *node)
 	WRITE_NODE_FIELD(appendplans);
 	WRITE_INT_FIELD(first_partial_plan);
 	WRITE_NODE_FIELD(partitioned_rels);
-	WRITE_NODE_FIELD(part_prune_infos);
+	WRITE_NODE_FIELD(part_prune_info);
 }
 
 static void
@@ -435,7 +435,7 @@ _outMergeAppend(StringInfo str, const MergeAppend *node)
 	for (i = 0; i < node->numCols; i++)
 		appendStringInfo(str, " %s", booltostr(node->nullsFirst[i]));
 
-	WRITE_NODE_FIELD(part_prune_infos);
+	WRITE_NODE_FIELD(part_prune_info);
 }
 
 static void
@@ -1015,9 +1015,18 @@ _outPlanRowMark(StringInfo str, const PlanRowMark *node)
 static void
 _outPartitionPruneInfo(StringInfo str, const PartitionPruneInfo *node)
 {
+	WRITE_NODE_TYPE("PARTITIONPRUNEINFO");
+
+	WRITE_NODE_FIELD(prune_infos);
+	WRITE_BITMAPSET_FIELD(other_subplans);
+}
+
+static void
+_outPartitionedRelPruneInfo(StringInfo str, const PartitionedRelPruneInfo *node)
+{
 	int			i;
 
-	WRITE_NODE_TYPE("PARTITIONPRUNEINFO");
+	WRITE_NODE_TYPE("PARTITIONEDRELPRUNEINFO");
 
 	WRITE_OID_FIELD(reloid);
 	WRITE_NODE_FIELD(pruning_steps);
@@ -3831,6 +3840,9 @@ outNode(StringInfo str, const void *obj)
 			case T_PartitionPruneInfo:
 				_outPartitionPruneInfo(str, obj);
 				break;
+			case T_PartitionedRelPruneInfo:
+				_outPartitionedRelPruneInfo(str, obj);
+				break;
 			case T_PartitionPruneStepOp:
 				_outPartitionPruneStepOp(str, obj);
 				break;
diff --git a/src/backend/nodes/readfuncs.c b/src/backend/nodes/readfuncs.c
index 9a01eb6b639..32545242239 100644
--- a/src/backend/nodes/readfuncs.c
+++ b/src/backend/nodes/readfuncs.c
@@ -1612,7 +1612,7 @@ _readAppend(void)
 	READ_NODE_FIELD(appendplans);
 	READ_INT_FIELD(first_partial_plan);
 	READ_NODE_FIELD(partitioned_rels);
-	READ_NODE_FIELD(part_prune_infos);
+	READ_NODE_FIELD(part_prune_info);
 
 	READ_DONE();
 }
@@ -1634,7 +1634,7 @@ _readMergeAppend(void)
 	READ_OID_ARRAY(sortOperators, local_node->numCols);
 	READ_OID_ARRAY(collations, local_node->numCols);
 	READ_BOOL_ARRAY(nullsFirst, local_node->numCols);
-	READ_NODE_FIELD(part_prune_infos);
+	READ_NODE_FIELD(part_prune_info);
 
 	READ_DONE();
 }
@@ -2329,6 +2329,17 @@ _readPartitionPruneInfo(void)
 {
 	READ_LOCALS(PartitionPruneInfo);
 
+	READ_NODE_FIELD(prune_infos);
+	READ_BITMAPSET_FIELD(other_subplans);
+
+	READ_DONE();
+}
+
+static PartitionedRelPruneInfo *
+_readPartitionedRelPruneInfo(void)
+{
+	READ_LOCALS(PartitionedRelPruneInfo);
+
 	READ_OID_FIELD(reloid);
 	READ_NODE_FIELD(pruning_steps);
 	READ_BITMAPSET_FIELD(present_parts);
@@ -2726,6 +2737,8 @@ parseNodeString(void)
 		return_value = _readPlanRowMark();
 	else if (MATCH("PARTITIONPRUNEINFO", 18))
 		return_value = _readPartitionPruneInfo();
+	else if (MATCH("PARTITIONEDRELPRUNEINFO", 23))
+		return_value = _readPartitionedRelPruneInfo();
 	else if (MATCH("PARTITIONPRUNESTEPOP", 20))
 		return_value = _readPartitionPruneStepOp();
 	else if (MATCH("PARTITIONPRUNESTEPCOMBINE", 25))
diff --git a/src/backend/optimizer/path/allpaths.c b/src/backend/optimizer/path/allpaths.c
index f04c30af456..0e80aeb65cd 100644
--- a/src/backend/optimizer/path/allpaths.c
+++ b/src/backend/optimizer/path/allpaths.c
@@ -1388,7 +1388,6 @@ add_paths_to_append_rel(PlannerInfo *root, RelOptInfo *rel,
 	List	   *all_child_outers = NIL;
 	ListCell   *l;
 	List	   *partitioned_rels = NIL;
-	bool		build_partitioned_rels = false;
 	double		partial_rows = -1;
 
 	/* If appropriate, consider parallel append */
@@ -1413,10 +1412,11 @@ add_paths_to_append_rel(PlannerInfo *root, RelOptInfo *rel,
 	if (rel->part_scheme != NULL)
 	{
 		if (IS_SIMPLE_REL(rel))
-			partitioned_rels = rel->partitioned_child_rels;
+			partitioned_rels = list_make1(rel->partitioned_child_rels);
 		else if (IS_JOIN_REL(rel))
 		{
 			int			relid = -1;
+			List	   *partrels = NIL;
 
 			/*
 			 * For a partitioned joinrel, concatenate the component rels'
@@ -1430,16 +1430,16 @@ add_paths_to_append_rel(PlannerInfo *root, RelOptInfo *rel,
 				component = root->simple_rel_array[relid];
 				Assert(component->part_scheme != NULL);
 				Assert(list_length(component->partitioned_child_rels) >= 1);
-				partitioned_rels =
-					list_concat(partitioned_rels,
+				partrels =
+					list_concat(partrels,
 								list_copy(component->partitioned_child_rels));
 			}
+
+			partitioned_rels = list_make1(partrels);
 		}
 
 		Assert(list_length(partitioned_rels) >= 1);
 	}
-	else if (rel->rtekind == RTE_SUBQUERY)
-		build_partitioned_rels = true;
 
 	/*
 	 * For every non-dummy child, remember the cheapest path.  Also, identify
@@ -1453,17 +1453,12 @@ add_paths_to_append_rel(PlannerInfo *root, RelOptInfo *rel,
 		Path	   *cheapest_partial_path = NULL;
 
 		/*
-		 * If we need to build partitioned_rels, accumulate the partitioned
-		 * rels for this child.  We must ensure that parents are always listed
-		 * before their child partitioned tables.
+		 * For UNION ALLs with non-empty partitioned_child_rels, accumulate
+		 * the Lists of child relations.
 		 */
-		if (build_partitioned_rels)
-		{
-			List	   *cprels = childrel->partitioned_child_rels;
-
-			partitioned_rels = list_concat(partitioned_rels,
-										   list_copy(cprels));
-		}
+		if (rel->rtekind == RTE_SUBQUERY && childrel->partitioned_child_rels != NIL)
+			partitioned_rels = lappend(partitioned_rels,
+									   childrel->partitioned_child_rels);
 
 		/*
 		 * If child has an unparameterized cheapest-total path, add that to
diff --git a/src/backend/optimizer/plan/createplan.c b/src/backend/optimizer/plan/createplan.c
index 0a0bec3bfcc..ae41c9efa07 100644
--- a/src/backend/optimizer/plan/createplan.c
+++ b/src/backend/optimizer/plan/createplan.c
@@ -124,6 +124,7 @@ static BitmapHeapScan *create_bitmap_scan_plan(PlannerInfo *root,
 static Plan *create_bitmap_subplan(PlannerInfo *root, Path *bitmapqual,
 					  List **qual, List **indexqual, List **indexECs);
 static void bitmap_subplan_mark_shared(Plan *plan);
+static List *flatten_partitioned_rels(List *partitioned_rels);
 static TidScan *create_tidscan_plan(PlannerInfo *root, TidPath *best_path,
 					List *tlist, List *scan_clauses);
 static SubqueryScan *create_subqueryscan_plan(PlannerInfo *root,
@@ -202,7 +203,8 @@ static NamedTuplestoreScan *make_namedtuplestorescan(List *qptlist, List *qpqual
 static WorkTableScan *make_worktablescan(List *qptlist, List *qpqual,
 				   Index scanrelid, int wtParam);
 static Append *make_append(List *appendplans, int first_partial_plan,
-			List *tlist, List *partitioned_rels, List *partpruneinfos);
+			List *tlist, List *partitioned_rels,
+			PartitionPruneInfo *partpruneinfo);
 static RecursiveUnion *make_recursive_union(List *tlist,
 					 Plan *lefttree,
 					 Plan *righttree,
@@ -1030,7 +1032,7 @@ create_append_plan(PlannerInfo *root, AppendPath *best_path)
 	List	   *subplans = NIL;
 	ListCell   *subpaths;
 	RelOptInfo *rel = best_path->path.parent;
-	List	   *partpruneinfos = NIL;
+	PartitionPruneInfo *partpruneinfo = NULL;
 
 	/*
 	 * The subpaths list could be empty, if every child was proven empty by
@@ -1070,8 +1072,8 @@ create_append_plan(PlannerInfo *root, AppendPath *best_path)
 
 	/*
 	 * If any quals exist, they may be useful to perform further partition
-	 * pruning during execution.  Gather information needed by the executor
-	 * to do partition pruning.
+	 * pruning during execution.  Gather information needed by the executor to
+	 * do partition pruning.
 	 */
 	if (enable_partition_pruning &&
 		rel->reloptkind == RELOPT_BASEREL &&
@@ -1093,10 +1095,11 @@ create_append_plan(PlannerInfo *root, AppendPath *best_path)
 		}
 
 		if (prunequal != NIL)
-			partpruneinfos =
-				make_partition_pruneinfo(root,
+			partpruneinfo =
+				make_partition_pruneinfo(root, rel,
+										 best_path->subpaths,
 										 best_path->partitioned_rels,
-										 best_path->subpaths, prunequal);
+										 prunequal);
 	}
 
 	/*
@@ -1108,7 +1111,7 @@ create_append_plan(PlannerInfo *root, AppendPath *best_path)
 
 	plan = make_append(subplans, best_path->first_partial_path,
 					   tlist, best_path->partitioned_rels,
-					   partpruneinfos);
+					   partpruneinfo);
 
 	copy_generic_path_info(&plan->plan, (Path *) best_path);
 
@@ -1132,7 +1135,7 @@ create_merge_append_plan(PlannerInfo *root, MergeAppendPath *best_path)
 	List	   *subplans = NIL;
 	ListCell   *subpaths;
 	RelOptInfo *rel = best_path->path.parent;
-	List	   *partpruneinfos = NIL;
+	PartitionPruneInfo *partpruneinfo = NULL;
 
 	/*
 	 * We don't have the actual creation of the MergeAppend node split out
@@ -1220,8 +1223,8 @@ create_merge_append_plan(PlannerInfo *root, MergeAppendPath *best_path)
 
 	/*
 	 * If any quals exist, they may be useful to perform further partition
-	 * pruning during execution.  Gather information needed by the executor
-	 * to do partition pruning.
+	 * pruning during execution.  Gather information needed by the executor to
+	 * do partition pruning.
 	 */
 	if (enable_partition_pruning &&
 		rel->reloptkind == RELOPT_BASEREL &&
@@ -1244,14 +1247,16 @@ create_merge_append_plan(PlannerInfo *root, MergeAppendPath *best_path)
 		}
 
 		if (prunequal != NIL)
-			partpruneinfos = make_partition_pruneinfo(root,
-													  best_path->partitioned_rels,
-													  best_path->subpaths, prunequal);
+			partpruneinfo = make_partition_pruneinfo(root, rel,
+													 best_path->subpaths,
+													 best_path->partitioned_rels,
+													 prunequal);
 	}
 
-	node->partitioned_rels = best_path->partitioned_rels;
+	node->partitioned_rels =
+		flatten_partitioned_rels(best_path->partitioned_rels);
 	node->mergeplans = subplans;
-	node->part_prune_infos = partpruneinfos;
+	node->part_prune_info = partpruneinfo;
 
 	return (Plan *) node;
 }
@@ -5000,6 +5005,27 @@ bitmap_subplan_mark_shared(Plan *plan)
 		elog(ERROR, "unrecognized node type: %d", nodeTag(plan));
 }
 
+/*
+ * flatten_partitioned_rels
+ *		Convert List of Lists into a single List with all elements from the
+ *		sub-lists.
+ */
+static List *
+flatten_partitioned_rels(List *partitioned_rels)
+{
+	List	   *newlist = NIL;
+	ListCell   *lc;
+
+	foreach(lc, partitioned_rels)
+	{
+		List	   *sublist = lfirst(lc);
+
+		newlist = list_concat(newlist, list_copy(sublist));
+	}
+
+	return newlist;
+}
+
 /*****************************************************************************
  *
  *	PLAN NODE BUILDING ROUTINES
@@ -5343,7 +5369,7 @@ make_foreignscan(List *qptlist,
 static Append *
 make_append(List *appendplans, int first_partial_plan,
 			List *tlist, List *partitioned_rels,
-			List *partpruneinfos)
+			PartitionPruneInfo *partpruneinfo)
 {
 	Append	   *node = makeNode(Append);
 	Plan	   *plan = &node->plan;
@@ -5354,8 +5380,8 @@ make_append(List *appendplans, int first_partial_plan,
 	plan->righttree = NULL;
 	node->appendplans = appendplans;
 	node->first_partial_plan = first_partial_plan;
-	node->partitioned_rels = partitioned_rels;
-	node->part_prune_infos = partpruneinfos;
+	node->partitioned_rels = flatten_partitioned_rels(partitioned_rels);
+	node->part_prune_info = partpruneinfo;
 	return node;
 }
 
@@ -6512,7 +6538,7 @@ make_modifytable(PlannerInfo *root,
 	node->operation = operation;
 	node->canSetTag = canSetTag;
 	node->nominalRelation = nominalRelation;
-	node->partitioned_rels = partitioned_rels;
+	node->partitioned_rels = flatten_partitioned_rels(partitioned_rels);
 	node->partColsUpdated = partColsUpdated;
 	node->resultRelations = resultRelations;
 	node->resultRelIndex = -1;	/* will be set correctly in setrefs.c */
diff --git a/src/backend/optimizer/plan/planner.c b/src/backend/optimizer/plan/planner.c
index df4ec448cb0..fd06da98b9f 100644
--- a/src/backend/optimizer/plan/planner.c
+++ b/src/backend/optimizer/plan/planner.c
@@ -1616,6 +1616,7 @@ inheritance_planner(PlannerInfo *root)
 		 * contain at least one member, that is, the root parent's index.
 		 */
 		Assert(list_length(partitioned_rels) >= 1);
+		partitioned_rels = list_make1(partitioned_rels);
 	}
 
 	/* Create Path representing a ModifyTable to do the UPDATE/DELETE work */
diff --git a/src/backend/partitioning/partprune.c b/src/backend/partitioning/partprune.c
index bfacc2ce297..752810d0e42 100644
--- a/src/backend/partitioning/partprune.c
+++ b/src/backend/partitioning/partprune.c
@@ -112,6 +112,11 @@ typedef struct PruneStepResult
 } PruneStepResult;
 
 
+static List *make_partitionedrel_pruneinfo(PlannerInfo *root,
+							  RelOptInfo *parentrel,
+							  int *relid_subplan_map,
+							  List *partitioned_rels, List *prunequal,
+							  Bitmapset **matchedsubplans);
 static List *gen_partprune_steps(RelOptInfo *rel, List *clauses,
 					bool *contradictory);
 static List *gen_partprune_steps_internal(GeneratePruningStepsContext *context,
@@ -160,7 +165,7 @@ static PruneStepResult *get_matching_range_bounds(PartitionPruneContext *context
 						  FmgrInfo *partsupfunc, Bitmapset *nullkeys);
 static Bitmapset *pull_exec_paramids(Expr *expr);
 static bool pull_exec_paramids_walker(Node *node, Bitmapset **context);
-static bool analyze_partkey_exprs(PartitionPruneInfo *pinfo, List *steps,
+static bool analyze_partkey_exprs(PartitionedRelPruneInfo *pinfo, List *steps,
 					  int partnatts);
 static PruneStepResult *perform_pruning_base_step(PartitionPruneContext *context,
 						  PartitionPruneStepOp *opstep);
@@ -176,38 +181,43 @@ static bool partkey_datum_from_expr(PartitionPruneContext *context,
 
 /*
  * make_partition_pruneinfo
- *		Build List of PartitionPruneInfos, one for each partitioned rel.
- *		These can be used in the executor to allow additional partition
- *		pruning to take place.
+ *		Builds a PartitionPruneInfo which can be used in the executor to allow
+ *		additional partition pruning to take place.  Returns NULL when
+ *		partition pruning would be useless.
  *
- * Here we generate partition pruning steps for 'prunequal' and also build a
- * data structure which allows mapping of partition indexes into 'subpaths'
- * indexes.
+ * 'parentrel' is the RelOptInfo for an appendrel, and 'subpaths' is the list
+ * of scan paths for its child rels.
  *
- * If no non-Const expressions are being compared to the partition key in any
- * of the 'partitioned_rels', then we return NIL to indicate no run-time
- * pruning should be performed.  Run-time pruning would be useless, since the
- * pruning done during planning will have pruned everything that can be.
+ * 'partitioned_rels' is a List containing Lists of relids of partitioned
+ * tables (a/k/a non-leaf partitions) that are parents of some of the child
+ * rels.  Here we attempt to populate the PartitionPruneInfo by adding a
+ * 'prune_infos' item for each sublist in the 'partitioned_rels' list.
+ * However, some of the sets of partitioned relations may not require any
+ * run-time pruning.  In these cases we'll simply not include a 'prune_infos'
+ * item for that set and instead we'll add all the subplans which belong to
+ * that set into the PartitionPruneInfo's 'other_subplans' field.  Callers
+ * will likely never want to prune subplans which are mentioned in this field.
+ *
+ * 'prunequal' is a list of potential pruning quals.
  */
-List *
-make_partition_pruneinfo(PlannerInfo *root, List *partitioned_rels,
-						 List *subpaths, List *prunequal)
+PartitionPruneInfo *
+make_partition_pruneinfo(PlannerInfo *root, RelOptInfo *parentrel,
+						 List *subpaths, List *partitioned_rels,
+						 List *prunequal)
 {
-	RelOptInfo *targetpart = NULL;
-	List	   *pinfolist = NIL;
-	bool		doruntimeprune = false;
+	PartitionPruneInfo *pruneinfo;
+	Bitmapset  *allmatchedsubplans = NULL;
 	int		   *relid_subplan_map;
-	int		   *relid_subpart_map;
 	ListCell   *lc;
+	List	   *prunerelinfos;
 	int			i;
 
 	/*
-	 * Construct two temporary arrays to map from planner relids to subplan
-	 * and sub-partition indexes.  For convenience, we use 1-based indexes
-	 * here, so that zero can represent an un-filled array entry.
+	 * Construct a temporary array to map from planner relids to subplan
+	 * indexes.  For convenience, we use 1-based indexes here, so that zero
+	 * can represent an un-filled array entry.
 	 */
 	relid_subplan_map = palloc0(sizeof(int) * root->simple_rel_array_size);
-	relid_subpart_map = palloc0(sizeof(int) * root->simple_rel_array_size);
 
 	/*
 	 * relid_subplan_map maps relid of a leaf partition to the index in
@@ -227,10 +237,107 @@ make_partition_pruneinfo(PlannerInfo *root, List *partitioned_rels,
 		relid_subplan_map[pathrel->relid] = i++;
 	}
 
+	/* We now build a PartitionedRelPruneInfo for each partitioned rel. */
+	prunerelinfos = NIL;
+	foreach(lc, partitioned_rels)
+	{
+		List	   *rels = (List *) lfirst(lc);
+		List	   *pinfolist;
+		Bitmapset  *matchedsubplans = NULL;
+
+		pinfolist = make_partitionedrel_pruneinfo(root, parentrel,
+												  relid_subplan_map,
+												  rels, prunequal,
+												  &matchedsubplans);
+
+		/* When pruning is possible, record the matched subplans */
+		if (pinfolist != NIL)
+		{
+			prunerelinfos = lappend(prunerelinfos, pinfolist);
+			allmatchedsubplans = bms_join(matchedsubplans,
+										  allmatchedsubplans);
+		}
+	}
+
+	pfree(relid_subplan_map);
+
+	/*
+	 * If none of the partition hierarchies had any useful run-time pruning
+	 * quals, then we can just not bother with run-time pruning.
+	 */
+	if (prunerelinfos == NIL)
+		return NULL;
+
+	/* Else build the result data structure */
+	pruneinfo = makeNode(PartitionPruneInfo);
+	pruneinfo->prune_infos = prunerelinfos;
+
+	/*
+	 * Some subplans may not belong to any of the listed partitioned rels.
+	 * This can happen for UNION ALL queries which include a non-partitioned
+	 * table, or when some of the hierarchies aren't run-time prunable.  Build
+	 * a bitmapset of the indexes of all such subplans, so that the executor
+	 * can identify which subplans should never be pruned.
+	 */
+	if (bms_num_members(allmatchedsubplans) < list_length(subpaths))
+	{
+		Bitmapset  *other_subplans;
+
+		/* Create the complement of allmatchedsubplans */
+		other_subplans = bms_add_range(NULL, 0, list_length(subpaths) - 1);
+		other_subplans = bms_del_members(other_subplans, allmatchedsubplans);
+
+		pruneinfo->other_subplans = other_subplans;
+	}
+	else
+		pruneinfo->other_subplans = NULL;
+
+	return pruneinfo;
+}
+
+/*
+ * make_partitionedrel_pruneinfo
+ *		Build a List of PartitionedRelPruneInfos, one for each partitioned
+ *		rel.  These can be used in the executor to allow additional partition
+ *		pruning to take place.
+ *
+ * Here we generate partition pruning steps for 'prunequal' and also build a
+ * data structure which allows mapping of partition indexes into 'subpaths'
+ * indexes.
+ *
+ * If no non-Const expressions are being compared to the partition key in any
+ * of the 'partitioned_rels', then we return NIL to indicate no run-time
+ * pruning should be performed.  Run-time pruning would be useless since the
+ * pruning done during planning will have pruned everything that can be.
+ *
+ * On non-NIL return, 'matchedsubplans' is set to the subplan indexes which
+ * were matched to this partition hierarchy.
+ */
+static List *
+make_partitionedrel_pruneinfo(PlannerInfo *root, RelOptInfo *parentrel,
+							  int *relid_subplan_map,
+							  List *partitioned_rels, List *prunequal,
+							  Bitmapset **matchedsubplans)
+{
+	RelOptInfo *targetpart = NULL;
+	List	   *pinfolist = NIL;
+	bool		doruntimeprune = false;
+	int		   *relid_subpart_map;
+	Bitmapset  *subplansfound = NULL;
+	ListCell   *lc;
+	int			i;
+
+	/*
+	 * Construct a temporary array to map from planner relids to index of the
+	 * partitioned_rel.  For convenience, we use 1-based indexes here, so that
+	 * zero can represent an un-filled array entry.
+	 */
+	relid_subpart_map = palloc0(sizeof(int) * root->simple_rel_array_size);
+
 	/*
 	 * relid_subpart_map maps relid of a non-leaf partition to the index in
 	 * 'partitioned_rels' of that rel (which will also be the index in the
-	 * returned PartitionPruneInfo list of the info for that partition).
+	 * returned PartitionedRelPruneInfo list of the info for that partition).
 	 */
 	i = 1;
 	foreach(lc, partitioned_rels)
@@ -246,12 +353,12 @@ make_partition_pruneinfo(PlannerInfo *root, List *partitioned_rels,
 		relid_subpart_map[rti] = i++;
 	}
 
-	/* We now build a PartitionPruneInfo for each partitioned rel */
+	/* We now build a PartitionedRelPruneInfo for each partitioned rel */
 	foreach(lc, partitioned_rels)
 	{
 		Index		rti = lfirst_int(lc);
 		RelOptInfo *subpart = find_base_rel(root, rti);
-		PartitionPruneInfo *pinfo;
+		PartitionedRelPruneInfo *pinfo;
 		RangeTblEntry *rte;
 		Bitmapset  *present_parts;
 		int			nparts = subpart->nparts;
@@ -263,12 +370,35 @@ make_partition_pruneinfo(PlannerInfo *root, List *partitioned_rels,
 		bool		contradictory;
 
 		/*
-		 * The first item in the list is the target partitioned relation.  The
-		 * quals belong to this relation, so require no translation.
+		 * The first item in the list is the target partitioned relation.
 		 */
 		if (!targetpart)
 		{
 			targetpart = subpart;
+
+			/*
+			 * The prunequal is presented to us as a qual for 'parentrel'.
+			 * Frequently this rel is the same as targetpart, so we can skip
+			 * an adjust_appendrel_attrs step.  But it might not be, and then
+			 * we have to translate.  We update the prunequal parameter here,
+			 * because in later iterations of the loop for child partitions,
+			 * we want to translate from parent to child variables.
+			 */
+			if (parentrel != subpart)
+			{
+				int			nappinfos;
+				AppendRelInfo **appinfos = find_appinfos_by_relids(root,
+																   subpart->relids,
+																   &nappinfos);
+
+				prunequal = (List *) adjust_appendrel_attrs(root, (Node *)
+															prunequal,
+															nappinfos,
+															appinfos);
+
+				pfree(appinfos);
+			}
+
 			partprunequal = prunequal;
 		}
 		else
@@ -320,13 +450,20 @@ make_partition_pruneinfo(PlannerInfo *root, List *partitioned_rels,
 
 			subplan_map[i] = subplanidx;
 			subpart_map[i] = subpartidx;
-			if (subplanidx >= 0 || subpartidx >= 0)
+			if (subplanidx >= 0)
+			{
+				present_parts = bms_add_member(present_parts, i);
+
+				/* Record finding this subplan  */
+				subplansfound = bms_add_member(subplansfound, subplanidx);
+			}
+			else if (subpartidx >= 0)
 				present_parts = bms_add_member(present_parts, i);
 		}
 
 		rte = root->simple_rte_array[subpart->relid];
 
-		pinfo = makeNode(PartitionPruneInfo);
+		pinfo = makeNode(PartitionedRelPruneInfo);
 		pinfo->reloid = rte->relid;
 		pinfo->pruning_steps = pruning_steps;
 		pinfo->present_parts = present_parts;
@@ -341,14 +478,17 @@ make_partition_pruneinfo(PlannerInfo *root, List *partitioned_rels,
 		pinfolist = lappend(pinfolist, pinfo);
 	}
 
-	pfree(relid_subplan_map);
 	pfree(relid_subpart_map);
 
-	if (doruntimeprune)
-		return pinfolist;
+	if (!doruntimeprune)
+	{
+		/* No run-time pruning required. */
+		return NIL;
+	}
+
+	*matchedsubplans = subplansfound;
 
-	/* No run-time pruning required. */
-	return NIL;
+	return pinfolist;
 }
 
 /*
@@ -2772,7 +2912,8 @@ pull_exec_paramids_walker(Node *node, Bitmapset **context)
  * level.  Also fills fields of *pinfo to record how to process each step.
  */
 static bool
-analyze_partkey_exprs(PartitionPruneInfo *pinfo, List *steps, int partnatts)
+analyze_partkey_exprs(PartitionedRelPruneInfo *pinfo, List *steps,
+					  int partnatts)
 {
 	bool		doruntimeprune = false;
 	ListCell   *lc;