Disable the recently-added use_physical_tlist optimization in cases

where the table contains dropped columns.  If the columns are dropped,
then their types may be gone as well, which causes ExecTypeFromTL() to
fail if the dropped columns appear in a plan node's tlist.  This could
be worked around but I don't think the optimization is valuable enough
to be worth the trouble.

src/backend/optimizer/plan/createplan.c

@@ -10,7 +10,7 @@
  *
  *
  * IDENTIFICATION
- *	  $Header: /cvsroot/pgsql/src/backend/optimizer/plan/createplan.c,v 1.139 2003/05/06 00:20:32 tgl Exp $
+ *	  $Header: /cvsroot/pgsql/src/backend/optimizer/plan/createplan.c,v 1.140 2003/05/11 15:03:52 tgl Exp $
  *
  *-------------------------------------------------------------------------
  */
@@ -295,6 +295,12 @@ use_physical_tlist(RelOptInfo *rel)
 	 */
 	if (rel->reloptkind != RELOPT_BASEREL)
 		return false;
+	/*
+	 * Can't do it if relation contains dropped columns.  This is detected
+	 * in plancat.c, see notes there.
+	 */
+	if (rel->varlist == NIL)
+		return false;
 	/*
 	 * Can't do it if any system columns are requested, either.  (This could
 	 * possibly be fixed but would take some fragile assumptions in setrefs.c,

src/backend/optimizer/util/plancat.c

@@ -9,7 +9,7 @@
  *
  *
  * IDENTIFICATION
- *	  $Header: /cvsroot/pgsql/src/backend/optimizer/util/plancat.c,v 1.79 2003/02/09 06:56:27 tgl Exp $
+ *	  $Header: /cvsroot/pgsql/src/backend/optimizer/util/plancat.c,v 1.80 2003/05/11 15:03:52 tgl Exp $
  *
  *-------------------------------------------------------------------------
  */
@@ -62,8 +62,15 @@ get_relation_info(Oid relationObjectId, RelOptInfo *rel)
 	relation = heap_open(relationObjectId, AccessShareLock);
 
 	/*
-	 * Make list of physical Vars.  Note we do NOT ignore dropped columns;
+	 * Make list of physical Vars.  But if there are any dropped columns,
-	 * the intent is to model the physical tuples of the relation.
+	 * punt and set varlist to NIL.  (XXX Ideally we would like to include
+	 * dropped columns so that the varlist models the physical tuples
+	 * of the relation.  However this creates problems for ExecTypeFromTL,
+	 * which may be asked to build a tupdesc for a tlist that includes vars
+	 * of no-longer-existent types.  In theory we could dig out the required
+	 * info from the pg_attribute entries of the relation, but that data is
+	 * not readily available to ExecTypeFromTL.  For now, punt and don't
+	 * apply the physical-tlist optimization when there are dropped cols.)
 	 */
 	numattrs = RelationGetNumberOfAttributes(relation);
 
@@ -71,6 +78,13 @@ get_relation_info(Oid relationObjectId, RelOptInfo *rel)
 	{
 		Form_pg_attribute att_tup = relation->rd_att->attrs[attrno - 1];
 
+		if (att_tup->attisdropped)
+		{
+			/* found a dropped col, so punt */
+			varlist = NIL;
+			break;
+		}
+
 		varlist = lappend(varlist,
 						  makeVar(varno,
 								  attrno,