1 files changed, 24 insertions, 10 deletions

diff --git a/src/backend/utils/adt/ruleutils.c b/src/backend/utils/adt/ruleutils.c
index 4c83cae5e92..13685a0a0e4 100644
--- a/src/backend/utils/adt/ruleutils.c
+++ b/src/backend/utils/adt/ruleutils.c
@@ -5370,19 +5370,20 @@ get_select_query_def(Query *query, deparse_context *context,
 }
 
 /*
- * Detect whether query looks like SELECT ... FROM VALUES();
- * if so, return the VALUES RTE.  Otherwise return NULL.
+ * Detect whether query looks like SELECT ... FROM VALUES(),
+ * with no need to rename the output columns of the VALUES RTE.
+ * If so, return the VALUES RTE.  Otherwise return NULL.
  */
 static RangeTblEntry *
-get_simple_values_rte(Query *query)
+get_simple_values_rte(Query *query, TupleDesc resultDesc)
 {
 	RangeTblEntry *result = NULL;
 	ListCell   *lc;
 
 	/*
-	 * We want to return true even if the Query also contains OLD or NEW rule
-	 * RTEs.  So the idea is to scan the rtable and see if there is only one
-	 * inFromCl RTE that is a VALUES RTE.
+	 * We want to detect a match even if the Query also contains OLD or NEW
+	 * rule RTEs.  So the idea is to scan the rtable and see if there is only
+	 * one inFromCl RTE that is a VALUES RTE.
 	 */
 	foreach(lc, query->rtable)
 	{
@@ -5405,23 +5406,36 @@ get_simple_values_rte(Query *query)
 	 * parser/analyze.c will never generate a "bare" VALUES RTE --- they only
 	 * appear inside auto-generated sub-queries with very restricted
 	 * structure.  However, DefineView might have modified the tlist by
-	 * injecting new column aliases; so compare tlist resnames against the
-	 * RTE's names to detect that.
+	 * injecting new column aliases, or we might have some other column
+	 * aliases forced by a resultDesc.  We can only simplify if the RTE's
+	 * column names match the names that get_target_list() would select.
 	 */
 	if (result)
 	{
 		ListCell   *lcn;
+		int			colno;
 
 		if (list_length(query->targetList) != list_length(result->eref->colnames))
 			return NULL;		/* this probably cannot happen */
+		colno = 0;
 		forboth(lc, query->targetList, lcn, result->eref->colnames)
 		{
 			TargetEntry *tle = (TargetEntry *) lfirst(lc);
 			char	   *cname = strVal(lfirst(lcn));
+			char	   *colname;
 
 			if (tle->resjunk)
 				return NULL;	/* this probably cannot happen */
-			if (tle->resname == NULL || strcmp(tle->resname, cname) != 0)
+
+			/* compute name that get_target_list would use for column */
+			colno++;
+			if (resultDesc && colno <= resultDesc->natts)
+				colname = NameStr(TupleDescAttr(resultDesc, colno - 1)->attname);
+			else
+				colname = tle->resname;
+
+			/* does it match the VALUES RTE? */
+			if (colname == NULL || strcmp(colname, cname) != 0)
 				return NULL;	/* column name has been changed */
 		}
 	}
@@ -5449,7 +5463,7 @@ get_basic_select_query(Query *query, deparse_context *context,
 	 * VALUES part.  This reverses what transformValuesClause() did at parse
 	 * time.
 	 */
-	values_rte = get_simple_values_rte(query);
+	values_rte = get_simple_values_rte(query, resultDesc);
 	if (values_rte)
 	{
 		get_values_def(values_rte->values_lists, context);