Fix failure with whole-row reference to a subquery.

tglsfdc · tglsfdc · commit ebefbb5fdeba · 2013-11-11T16:36:27.000-05:00
Simple oversight in commit 1cb108e --- recursively examining a subquery output column is only sane if the original Var refers to a single output column. Found by Kevin Grittner.
diff --git a/src/backend/utils/adt/selfuncs.c b/src/backend/utils/adt/selfuncs.c
@@ -4505,6 +4505,12 @@ examine_simple_variable(PlannerInfo *root, Var *var,
 		RelOptInfo *rel;
 		TargetEntry *ste;
 
+		/*
+		 * Punt if it's a whole-row var rather than a plain column reference.
+		 */
+		if (var->varattno == InvalidAttrNumber)
+			return;
+
 		/*
 		 * Punt if subquery uses set operations or GROUP BY, as these will
 		 * mash underlying columns' stats beyond recognition.  (Set ops are
