lansz
diff --git a/‎src/test/regress/expected/subselect.out
Lines changed: 18 additions & 0 deletions b/‎src/test/regress/expected/subselect.out
Lines changed: 18 additions & 0 deletions
diff --git a/‎src/test/regress/sql/subselect.sql
Lines changed: 10 additions & 0 deletions b/‎src/test/regress/sql/subselect.sql
Lines changed: 10 additions & 0 deletions
@@ -712,7 +712,6 @@ ExecEvalWholeRowVar(WholeRowVarExprState *wrvstate, ExprContext *econtext,
 {
 	Var		   *variable = (Var *) wrvstate->xprstate.expr;
 	TupleTableSlot *slot;
-	TupleDesc	slot_tupdesc;
 	bool		needslow = false;
 
 	if (isDone)
@@ -790,25 +789,14 @@ ExecEvalWholeRowVar(WholeRowVarExprState *wrvstate, ExprContext *econtext,
 	if (wrvstate->wrv_junkFilter != NULL)
 		slot = ExecFilterJunk(wrvstate->wrv_junkFilter, slot);
 
-	slot_tupdesc = slot->tts_tupleDescriptor;
-
 	/*
-	 * If it's a RECORD Var, we'll use the slot's type ID info.  It's likely
-	 * that the slot's type is also RECORD; if so, make sure it's been
-	 * "blessed", so that the Datum can be interpreted later.
-	 *
 	 * If the Var identifies a named composite type, we must check that the
 	 * actual tuple type is compatible with it.
 	 */
-	if (variable->vartype == RECORDOID)
-	{
-		if (slot_tupdesc->tdtypeid == RECORDOID &&
-			slot_tupdesc->tdtypmod < 0)
-			assign_record_type_typmod(slot_tupdesc);
-	}
-	else
+	if (variable->vartype != RECORDOID)
 	{
 		TupleDesc	var_tupdesc;
+		TupleDesc	slot_tupdesc;
 		int			i;
 
 		/*
@@ -825,6 +813,8 @@ ExecEvalWholeRowVar(WholeRowVarExprState *wrvstate, ExprContext *econtext,
 		 */
 		var_tupdesc = lookup_rowtype_tupdesc(variable->vartype, -1);
 
+		slot_tupdesc = slot->tts_tupleDescriptor;
+
 		if (var_tupdesc->natts != slot_tupdesc->natts)
 			ereport(ERROR,
 					(errcode(ERRCODE_DATATYPE_MISMATCH),
@@ -882,6 +872,7 @@ ExecEvalWholeRowFast(WholeRowVarExprState *wrvstate, ExprContext *econtext,
 {
 	Var		   *variable = (Var *) wrvstate->xprstate.expr;
 	TupleTableSlot *slot = econtext->ecxt_scantuple;
+	TupleDesc	slot_tupdesc;
 	HeapTupleHeader dtuple;
 
 	if (isDone)
@@ -892,6 +883,20 @@ ExecEvalWholeRowFast(WholeRowVarExprState *wrvstate, ExprContext *econtext,
 	if (wrvstate->wrv_junkFilter != NULL)
 		slot = ExecFilterJunk(wrvstate->wrv_junkFilter, slot);
 
+	/*
+	 * If it's a RECORD Var, we'll use the slot's type ID info.  It's likely
+	 * that the slot's type is also RECORD; if so, make sure it's been
+	 * "blessed", so that the Datum can be interpreted later.  (Note: we must
+	 * do this here, not in ExecEvalWholeRowVar, because some plan trees may
+	 * return different slots at different times.  We have to be ready to
+	 * bless additional slots during the run.)
+	 */
+	slot_tupdesc = slot->tts_tupleDescriptor;
+	if (variable->vartype == RECORDOID &&
+		slot_tupdesc->tdtypeid == RECORDOID &&
+		slot_tupdesc->tdtypmod < 0)
+		assign_record_type_typmod(slot_tupdesc);
+
 	/*
 	 * Copy the slot tuple and make sure any toasted fields get detoasted.
 	 */
 
@@ -662,3 +662,21 @@ select * from int4_tbl o where (f1, f1) in
 (1 row)
 
 reset enable_hashjoin;
+--
+-- check for over-optimization of whole-row Var referencing an Append plan
+--
+select (select q from
+         (select 1,2,3 where f1 > 0
+          union all
+          select 4,5,6.0 where f1 <= 0
+         ) q )
+from int4_tbl;
+ ?column?  
+-----------
+ (4,5,6.0)
+ (1,2,3)
+ (4,5,6.0)
+ (1,2,3)
+ (4,5,6.0)
+(5 rows)
+
@@ -404,3 +404,13 @@ set enable_hashjoin to 0;
 select * from int4_tbl o where (f1, f1) in
   (select f1, generate_series(1,2) / 10 g from int4_tbl i group by f1);
 reset enable_hashjoin;
+
+--
+-- check for over-optimization of whole-row Var referencing an Append plan
+--
+select (select q from
+         (select 1,2,3 where f1 > 0
+          union all
+          select 4,5,6.0 where f1 <= 0
+         ) q )
+from int4_tbl;