[AQUMV] Check relation actually has children when view matching.

We arbitrarily set inh to false with a FIXME before this commit.
It should be corrected later during planning, but it's earlier
as we are doing view matching on parse tree.
Correct inh and skip it if has children.

Authored-by: Zhang Mingli avamingli@gmail.com

Author: avamingli

src/backend/optimizer/plan/aqumv.c

@@ -254,6 +254,13 @@ answer_query_using_materialized_views(PlannerInfo *root,
 		if (mvrte->relid != origin_rel_oid)
 			continue;
 
+		/*
+		 * Check if it actually has children here to match before planning.
+		 */
+		mvrte->inh = has_subclass(mvrte->relid);
+		if (mvrte->inh)
+			continue;
+
 		subroot = (PlannerInfo *) palloc(sizeof(PlannerInfo));
 		memcpy(subroot, root, sizeof(PlannerInfo));
 		subroot->parent_root = root;
@@ -371,11 +378,6 @@ answer_query_using_materialized_views(PlannerInfo *root,
 		/* Rewrite with mv's query tree*/
 		mvrte->relkind = RELKIND_MATVIEW;
 		mvrte->relid = matviewRel->rd_rel->oid;
-		/*
-		 * AQUMV_FIXME_MVP
-		 * Not sure where it's true from actions even it's not inherit tables.
-		 */
-		mvrte->inh = false;
 		viewQuery->rtable = list_make1(mvrte); /* rewrite to SELECT FROM mv itself. */
 		viewQuery->jointree->quals = (Node *)post_quals; /* Could be NULL, but doesn'y matter for now. */