Fix interaction of triggers, partitioning, and EXPLAIN ANALYZE.

Add a new EState member es_leaf_result_relations, so that the trigger
code knows about ResultRelInfos created by tuple routing.  Also make
sure ExplainPrintTriggers knows about partition-related
ResultRelInfos.

Etsuro Fujita, reviewed by Amit Langote

Discussion: http://postgr.es/m/57163e18-8e56-da83-337a-22f2c0008051@lab.ntt.co.jp

src/backend/commands/copy.c

@@ -1415,59 +1415,6 @@ BeginCopy(ParseState *pstate,
 					(errcode(ERRCODE_UNDEFINED_COLUMN),
 					 errmsg("table \"%s\" does not have OIDs",
 							RelationGetRelationName(cstate->rel))));
-
-		/*
-		 * If there are any triggers with transition tables on the named
-		 * relation, we need to be prepared to capture transition tuples.
-		 */
-		cstate->transition_capture = MakeTransitionCaptureState(rel->trigdesc);
-
-		/* Initialize state for CopyFrom tuple routing. */
-		if (is_from && rel->rd_rel->relkind == RELKIND_PARTITIONED_TABLE)
-		{
-			PartitionDispatch *partition_dispatch_info;
-			ResultRelInfo *partitions;
-			TupleConversionMap **partition_tupconv_maps;
-			TupleTableSlot *partition_tuple_slot;
-			int			num_parted,
-						num_partitions;
-
-			ExecSetupPartitionTupleRouting(rel,
-										   1,
-										   &partition_dispatch_info,
-										   &partitions,
-										   &partition_tupconv_maps,
-										   &partition_tuple_slot,
-										   &num_parted, &num_partitions);
-			cstate->partition_dispatch_info = partition_dispatch_info;
-			cstate->num_dispatch = num_parted;
-			cstate->partitions = partitions;
-			cstate->num_partitions = num_partitions;
-			cstate->partition_tupconv_maps = partition_tupconv_maps;
-			cstate->partition_tuple_slot = partition_tuple_slot;
-
-			/*
-			 * If we are capturing transition tuples, they may need to be
-			 * converted from partition format back to partitioned table
-			 * format (this is only ever necessary if a BEFORE trigger
-			 * modifies the tuple).
-			 */
-			if (cstate->transition_capture != NULL)
-			{
-				int			i;
-
-				cstate->transition_tupconv_maps = (TupleConversionMap **)
-					palloc0(sizeof(TupleConversionMap *) *
-							cstate->num_partitions);
-				for (i = 0; i < cstate->num_partitions; ++i)
-				{
-					cstate->transition_tupconv_maps[i] =
-						convert_tuples_by_name(RelationGetDescr(cstate->partitions[i].ri_RelationDesc),
-											   RelationGetDescr(rel),
-											   gettext_noop("could not convert row type"));
-				}
-			}
-		}
 	}
 	else
 	{
@@ -2482,6 +2429,63 @@ CopyFrom(CopyState cstate)
 	/* Triggers might need a slot as well */
 	estate->es_trig_tuple_slot = ExecInitExtraTupleSlot(estate);
 
+	/*
+	 * If there are any triggers with transition tables on the named relation,
+	 * we need to be prepared to capture transition tuples.
+	 */
+	cstate->transition_capture =
+		MakeTransitionCaptureState(cstate->rel->trigdesc);
+
+	/*
+	 * If the named relation is a partitioned table, initialize state for
+	 * CopyFrom tuple routing.
+	 */
+	if (cstate->rel->rd_rel->relkind == RELKIND_PARTITIONED_TABLE)
+	{
+		PartitionDispatch *partition_dispatch_info;
+		ResultRelInfo *partitions;
+		TupleConversionMap **partition_tupconv_maps;
+		TupleTableSlot *partition_tuple_slot;
+		int			num_parted,
+					num_partitions;
+
+		ExecSetupPartitionTupleRouting(cstate->rel,
+									   1,
+									   estate,
+									   &partition_dispatch_info,
+									   &partitions,
+									   &partition_tupconv_maps,
+									   &partition_tuple_slot,
+									   &num_parted, &num_partitions);
+		cstate->partition_dispatch_info = partition_dispatch_info;
+		cstate->num_dispatch = num_parted;
+		cstate->partitions = partitions;
+		cstate->num_partitions = num_partitions;
+		cstate->partition_tupconv_maps = partition_tupconv_maps;
+		cstate->partition_tuple_slot = partition_tuple_slot;
+
+		/*
+		 * If we are capturing transition tuples, they may need to be
+		 * converted from partition format back to partitioned table format
+		 * (this is only ever necessary if a BEFORE trigger modifies the
+		 * tuple).
+		 */
+		if (cstate->transition_capture != NULL)
+		{
+			int			i;
+
+			cstate->transition_tupconv_maps = (TupleConversionMap **)
+				palloc0(sizeof(TupleConversionMap *) * cstate->num_partitions);
+			for (i = 0; i < cstate->num_partitions; ++i)
+			{
+				cstate->transition_tupconv_maps[i] =
+					convert_tuples_by_name(RelationGetDescr(cstate->partitions[i].ri_RelationDesc),
+										   RelationGetDescr(cstate->rel),
+										   gettext_noop("could not convert row type"));
+			}
+		}
+	}
+
 	/*
 	 * It's more efficient to prepare a bunch of tuples for insertion, and
 	 * insert them in one heap_multi_insert() call, than call heap_insert()

src/backend/commands/explain.c

@@ -656,17 +656,30 @@ ExplainPrintTriggers(ExplainState *es, QueryDesc *queryDesc)
 	ResultRelInfo *rInfo;
 	bool		show_relname;
 	int			numrels = queryDesc->estate->es_num_result_relations;
+	int			numrootrels = queryDesc->estate->es_num_root_result_relations;
+	List	   *leafrels = queryDesc->estate->es_leaf_result_relations;
 	List	   *targrels = queryDesc->estate->es_trig_target_relations;
 	int			nr;
 	ListCell   *l;
 
 	ExplainOpenGroup("Triggers", "Triggers", false, es);
 
-	show_relname = (numrels > 1 || targrels != NIL);
+	show_relname = (numrels > 1 || numrootrels > 0 ||
+					leafrels != NIL || targrels != NIL);
 	rInfo = queryDesc->estate->es_result_relations;
 	for (nr = 0; nr < numrels; rInfo++, nr++)
 		report_triggers(rInfo, show_relname, es);
 
+	rInfo = queryDesc->estate->es_root_result_relations;
+	for (nr = 0; nr < numrootrels; rInfo++, nr++)
+		report_triggers(rInfo, show_relname, es);
+
+	foreach(l, leafrels)
+	{
+		rInfo = (ResultRelInfo *) lfirst(l);
+		report_triggers(rInfo, show_relname, es);
+	}
+
 	foreach(l, targrels)
 	{
 		rInfo = (ResultRelInfo *) lfirst(l);

src/backend/executor/execMain.c

@@ -1365,16 +1365,18 @@ InitResultRelInfo(ResultRelInfo *resultRelInfo,
  *
  * Get a ResultRelInfo for a trigger target relation.  Most of the time,
  * triggers are fired on one of the result relations of the query, and so
- * we can just return a member of the es_result_relations array.  (Note: in
- * self-join situations there might be multiple members with the same OID;
- * if so it doesn't matter which one we pick.)  However, it is sometimes
- * necessary to fire triggers on other relations; this happens mainly when an
- * RI update trigger queues additional triggers on other relations, which will
- * be processed in the context of the outer query.  For efficiency's sake,
- * we want to have a ResultRelInfo for those triggers too; that can avoid
- * repeated re-opening of the relation.  (It also provides a way for EXPLAIN
- * ANALYZE to report the runtimes of such triggers.)  So we make additional
- * ResultRelInfo's as needed, and save them in es_trig_target_relations.
+ * we can just return a member of the es_result_relations array, the
+ * es_root_result_relations array (if any), or the es_leaf_result_relations
+ * list (if any).  (Note: in self-join situations there might be multiple
+ * members with the same OID; if so it doesn't matter which one we pick.)
+ * However, it is sometimes necessary to fire triggers on other relations;
+ * this happens mainly when an RI update trigger queues additional triggers
+ * on other relations, which will be processed in the context of the outer
+ * query.  For efficiency's sake, we want to have a ResultRelInfo for those
+ * triggers too; that can avoid repeated re-opening of the relation.  (It
+ * also provides a way for EXPLAIN ANALYZE to report the runtimes of such
+ * triggers.)  So we make additional ResultRelInfo's as needed, and save them
+ * in es_trig_target_relations.
  */
 ResultRelInfo *
 ExecGetTriggerResultRel(EState *estate, Oid relid)
@@ -1395,6 +1397,23 @@ ExecGetTriggerResultRel(EState *estate, Oid relid)
 		rInfo++;
 		nr--;
 	}
+	/* Second, search through the root result relations, if any */
+	rInfo = estate->es_root_result_relations;
+	nr = estate->es_num_root_result_relations;
+	while (nr > 0)
+	{
+		if (RelationGetRelid(rInfo->ri_RelationDesc) == relid)
+			return rInfo;
+		rInfo++;
+		nr--;
+	}
+	/* Third, search through the leaf result relations, if any */
+	foreach(l, estate->es_leaf_result_relations)
+	{
+		rInfo = (ResultRelInfo *) lfirst(l);
+		if (RelationGetRelid(rInfo->ri_RelationDesc) == relid)
+			return rInfo;
+	}
 	/* Nope, but maybe we already made an extra ResultRelInfo for it */
 	foreach(l, estate->es_trig_target_relations)
 	{
@@ -3238,6 +3257,7 @@ EvalPlanQualEnd(EPQState *epqstate)
 void
 ExecSetupPartitionTupleRouting(Relation rel,
 							   Index resultRTindex,
+							   EState *estate,
 							   PartitionDispatch **pd,
 							   ResultRelInfo **partitions,
 							   TupleConversionMap ***tup_conv_maps,
@@ -3301,7 +3321,10 @@ ExecSetupPartitionTupleRouting(Relation rel,
 						  partrel,
 						  resultRTindex,
 						  rel,
-						  0);
+						  estate->es_instrument);
+
+		estate->es_leaf_result_relations =
+			lappend(estate->es_leaf_result_relations, leaf_part_rri);
 
 		/*
 		 * Open partition indices (remember we do not support ON CONFLICT in

src/backend/executor/execUtils.c

@@ -115,6 +115,11 @@ CreateExecutorState(void)
 	estate->es_num_result_relations = 0;
 	estate->es_result_relation_info = NULL;
 
+	estate->es_root_result_relations = NULL;
+	estate->es_num_root_result_relations = 0;
+
+	estate->es_leaf_result_relations = NIL;
+
 	estate->es_trig_target_relations = NIL;
 	estate->es_trig_tuple_slot = NULL;
 	estate->es_trig_oldtup_slot = NULL;

src/backend/executor/nodeModifyTable.c

@@ -1919,6 +1919,7 @@ ExecInitModifyTable(ModifyTable *node, EState *estate, int eflags)
 
 		ExecSetupPartitionTupleRouting(rel,
 									   node->nominalRelation,
+									   estate,
 									   &partition_dispatch_info,
 									   &partitions,
 									   &partition_tupconv_maps,

src/include/executor/executor.h

@@ -208,6 +208,7 @@ extern void EvalPlanQualSetTuple(EPQState *epqstate, Index rti,
 extern HeapTuple EvalPlanQualGetTuple(EPQState *epqstate, Index rti);
 extern void ExecSetupPartitionTupleRouting(Relation rel,
 							   Index resultRTindex,
+							   EState *estate,
 							   PartitionDispatch **pd,
 							   ResultRelInfo **partitions,
 							   TupleConversionMap ***tup_conv_maps,

src/include/nodes/execnodes.h

@@ -452,6 +452,9 @@ typedef struct EState
 	ResultRelInfo *es_root_result_relations;	/* array of ResultRelInfos */
 	int			es_num_root_result_relations;	/* length of the array */
 
+	/* Info about leaf partitions of partitioned table(s) for insert queries: */
+	List	   *es_leaf_result_relations;	/* List of ResultRelInfos */
+
 	/* Stuff used for firing triggers: */
 	List	   *es_trig_target_relations;	/* trigger-only ResultRelInfos */
 	TupleTableSlot *es_trig_tuple_slot; /* for trigger output tuples */