Blow out cached bounds of all children when parent is invalidated.

A concrete example where leaving them is not ok is
 - Range partition table
 - Delete entry from pathman_config (psin was blown, but bounds not)
 - Now hash partition table; bounds cache with uninitialized hash_idx is used.

While here, also spawn relcache inval message on delete from pathman_config, not
only from pathman_config_params.

init.sql

@@ -111,7 +111,7 @@ ALTER TABLE @extschema@.pathman_config ENABLE ROW LEVEL SECURITY;
 ALTER TABLE @extschema@.pathman_config_params ENABLE ROW LEVEL SECURITY;
 
 /*
- * Invalidate relcache every time someone changes parameters config.
+ * Invalidate relcache every time someone changes parameters config or pathman_config
  */
 CREATE OR REPLACE FUNCTION @extschema@.pathman_config_params_trigger_func()
 RETURNS TRIGGER AS 'pg_pathman', 'pathman_config_params_trigger_func'
@@ -121,6 +121,10 @@ CREATE TRIGGER pathman_config_params_trigger
 AFTER INSERT OR UPDATE OR DELETE ON @extschema@.pathman_config_params
 FOR EACH ROW EXECUTE PROCEDURE @extschema@.pathman_config_params_trigger_func();
 
+CREATE TRIGGER pathman_config_trigger
+AFTER INSERT OR UPDATE OR DELETE ON @extschema@.pathman_config
+FOR EACH ROW EXECUTE PROCEDURE @extschema@.pathman_config_params_trigger_func();
+
 /*
  * Enable dump of config tables with pg_dump.
  */

pg_pathman--1.4--1.5.sql

@@ -52,6 +52,10 @@ ALTER TABLE @extschema@.pathman_config ADD CONSTRAINT pathman_config_interval_ch
 											   parttype,
 											   range_interval));
 
+CREATE TRIGGER pathman_config_trigger
+AFTER INSERT OR UPDATE OR DELETE ON @extschema@.pathman_config
+FOR EACH ROW EXECUTE PROCEDURE @extschema@.pathman_config_params_trigger_func();
+
 /*
  * Get parsed and analyzed expression.
  */

src/hooks.c

@@ -874,7 +874,7 @@ pathman_relcache_hook(Datum arg, Oid relid)
 	else if (relid >= FirstNormalObjectId)
 	{
 		/* Invalidate PartBoundInfo entry if needed */
-		forget_bounds_of_partition(relid);
+		forget_bounds_of_rel(relid);
 
 		/* Invalidate PartParentInfo entry if needed */
 		forget_parent_of_partition(relid);

src/include/relation_info.h

@@ -367,7 +367,7 @@ void shout_if_prel_is_invalid(const Oid parent_oid,
 							  const PartType expected_part_type);
 
 /* Bounds cache */
-void forget_bounds_of_partition(Oid partition);
+void forget_bounds_of_rel(Oid partition);
 PartBoundInfo *get_bounds_of_partition(Oid partition, const PartRelationInfo *prel);
 Expr *get_partition_constraint_expr(Oid partition, bool raise_error);
 void invalidate_bounds_cache(void);

src/pl_funcs.c

@@ -904,14 +904,16 @@ pathman_config_params_trigger_func(PG_FUNCTION_ARGS)
 {
 	TriggerData	   *trigdata = (TriggerData *) fcinfo->context;
 	Oid				pathman_config_params;
+	Oid				pathman_config;
 	Oid				partrel;
 	Datum			partrel_datum;
 	bool			partrel_isnull;
 
 	/* Fetch Oid of PATHMAN_CONFIG_PARAMS */
 	pathman_config_params = get_pathman_config_params_relid(true);
+	pathman_config = get_pathman_config_relid(true);
 
-	/* Handle "pg_pathman.enabled = t" case */
+	/* Handle "pg_pathman.enabled = f" case */
 	if (!OidIsValid(pathman_config_params))
 		goto pathman_config_params_trigger_func_return;
 
@@ -925,12 +927,17 @@ pathman_config_params_trigger_func(PG_FUNCTION_ARGS)
 			 trigdata->tg_trigger->tgname);
 
 	/* Handle wrong relation */
-	if (RelationGetRelid(trigdata->tg_relation) != pathman_config_params)
-		elog(ERROR, "%s: must be fired for relation \"%s\"",
+	if (RelationGetRelid(trigdata->tg_relation) != pathman_config_params &&
+		RelationGetRelid(trigdata->tg_relation) != pathman_config)
+		elog(ERROR, "%s: must be fired for relation \"%s\" or \"%s\"",
 			 trigdata->tg_trigger->tgname,
-			 get_rel_name(pathman_config_params));
+			 get_rel_name(pathman_config_params),
+			 get_rel_name(pathman_config));
 
-	/* Extract partitioned relation's Oid */
+	/*
+	 * Extract partitioned relation's Oid.
+	 * Hacky: 1 is attrnum of relid for both pathman_config and pathman_config_params
+	 */
 	partrel_datum = heap_getattr(trigdata->tg_trigtuple,
 								 Anum_pathman_config_params_partrel,
 								 RelationGetDescr(trigdata->tg_relation),

src/relation_info.c

@@ -160,6 +160,8 @@ static void fill_pbin_with_bounds(PartBoundInfo *pbin,
 
 static int cmp_range_entries(const void *p1, const void *p2, void *arg);
 
+static void forget_bounds_of_partition(Oid partition);
+
 static bool query_contains_subqueries(Node *node, void *context);
 
 
@@ -929,7 +931,7 @@ PrelExpressionAttributesMap(const PartRelationInfo *prel,
  */
 
 /* Remove partition's constraint from cache */
-void
+static void
 forget_bounds_of_partition(Oid partition)
 {
 	PartBoundInfo *pbin;
@@ -953,6 +955,42 @@ forget_bounds_of_partition(Oid partition)
 								   HASH_REMOVE,
 								   NULL);
 	}
+
+}
+
+/*
+ * Remove rel's constraint from cache, if relid is partition;
+ * Remove all children constraints, if it is parent.
+ */
+void
+forget_bounds_of_rel(Oid relid)
+{
+	PartStatusInfo *psin;
+
+	forget_bounds_of_partition(relid);
+
+	/*
+	 * If it was the parent who got invalidated, purge children's bounds.
+	 * We assume here that if bounds_cache has something, parent must be also
+	 * in status_cache. Fragile, but seems better then blowing out full bounds
+	 * cache or digging pathman_config on each relcache invalidation.
+	 */
+
+	/* Find status cache entry for this relation */
+	psin = pathman_cache_search_relid(status_cache,
+									  relid, HASH_FIND,
+									  NULL);
+	if (psin != NULL && psin->prel != NULL)
+	{
+		uint32 i;
+		PartRelationInfo *prel = psin->prel;
+		Oid	   *children = PrelGetChildrenArray(prel);
+
+		for	(i = 0; i < PrelChildrenCount(prel); i++)
+		{
+			forget_bounds_of_partition(children[i]);
+		}
+	}
 }
 
 /* Return partition's constraint as expression tree */