Make the world very nearly safe for composite-type columns in tables.

1. Solve the problem of not having TOAST references hiding inside composite
values by establishing the rule that toasting only goes one level deep:
a tuple can contain toasted fields, but a composite-type datum that is
to be inserted into a tuple cannot.  Enforcing this in heap_formtuple
is relatively cheap and it avoids a large increase in the cost of running
the tuptoaster during final storage of a row.
2. Fix some interesting problems in expansion of inherited queries that
reference whole-row variables.  We never really did this correctly before,
but it's now relatively painless to solve by expanding the parent's
whole-row Var into a RowExpr() selecting the proper columns from the
child.
If you dike out the preventive check in CheckAttributeType(),
composite-type columns now seem to actually work.  However, we surely
cannot ship them like this --- without I/O for composite types, you
can't get pg_dump to dump tables containing them.  So a little more
work still to do.

3 files changed, 22 insertions, 10 deletions

diff --git a/src/backend/optimizer/path/allpaths.c b/src/backend/optimizer/path/allpaths.c
index dc428abdab9..24a51149e45 100644
--- a/src/backend/optimizer/path/allpaths.c
+++ b/src/backend/optimizer/path/allpaths.c
@@ -8,7 +8,7 @@
  *
  *
  * IDENTIFICATION
- *	  $PostgreSQL: pgsql/src/backend/optimizer/path/allpaths.c,v 1.117 2004/06/01 03:02:51 tgl Exp $
+ *	  $PostgreSQL: pgsql/src/backend/optimizer/path/allpaths.c,v 1.118 2004/06/05 01:55:04 tgl Exp $
  *
  *-------------------------------------------------------------------------
  */
@@ -302,11 +302,15 @@ set_inherited_rel_pathlist(Query *root, RelOptInfo *rel,
 		{
 			Var		   *parentvar = (Var *) lfirst(parentvars);
 			Var		   *childvar = (Var *) lfirst(childvars);
-			int			parentndx = parentvar->varattno - rel->min_attr;
-			int			childndx = childvar->varattno - childrel->min_attr;
 
-			if (childrel->attr_widths[childndx] > rel->attr_widths[parentndx])
-				rel->attr_widths[parentndx] = childrel->attr_widths[childndx];
+			if (IsA(parentvar, Var) && IsA(childvar, Var))
+			{
+				int			pndx = parentvar->varattno - rel->min_attr;
+				int			cndx = childvar->varattno - childrel->min_attr;
+
+				if (childrel->attr_widths[cndx] > rel->attr_widths[pndx])
+					rel->attr_widths[pndx] = childrel->attr_widths[cndx];
+			}
 		}
 	}
 
diff --git a/src/backend/optimizer/path/costsize.c b/src/backend/optimizer/path/costsize.c
index 46a323fade4..53bd8bdf5c5 100644
--- a/src/backend/optimizer/path/costsize.c
+++ b/src/backend/optimizer/path/costsize.c
@@ -49,7 +49,7 @@
  * Portions Copyright (c) 1994, Regents of the University of California
  *
  * IDENTIFICATION
- *	  $PostgreSQL: pgsql/src/backend/optimizer/path/costsize.c,v 1.129 2004/06/01 03:02:52 tgl Exp $
+ *	  $PostgreSQL: pgsql/src/backend/optimizer/path/costsize.c,v 1.130 2004/06/05 01:55:04 tgl Exp $
  *
  *-------------------------------------------------------------------------
  */
@@ -1704,11 +1704,18 @@ set_rel_width(Query *root, RelOptInfo *rel)
 	foreach(tllist, rel->reltargetlist)
 	{
 		Var		   *var = (Var *) lfirst(tllist);
-		int			ndx = var->varattno - rel->min_attr;
+		int			ndx;
 		Oid			relid;
 		int32		item_width;
 
-		Assert(IsA(var, Var));
+		/* For now, punt on whole-row child Vars */
+		if (!IsA(var, Var))
+		{
+			tuple_width += 32;	/* arbitrary */
+			continue;
+		}
+
+		ndx = var->varattno - rel->min_attr;
 
 		/*
 		 * The width probably hasn't been cached yet, but may as well
diff --git a/src/backend/optimizer/path/pathkeys.c b/src/backend/optimizer/path/pathkeys.c
index 363fe54450d..71f96c164e5 100644
--- a/src/backend/optimizer/path/pathkeys.c
+++ b/src/backend/optimizer/path/pathkeys.c
@@ -11,7 +11,7 @@
  * Portions Copyright (c) 1994, Regents of the University of California
  *
  * IDENTIFICATION
- *	  $PostgreSQL: pgsql/src/backend/optimizer/path/pathkeys.c,v 1.59 2004/06/01 03:02:52 tgl Exp $
+ *	  $PostgreSQL: pgsql/src/backend/optimizer/path/pathkeys.c,v 1.60 2004/06/05 01:55:04 tgl Exp $
  *
  *-------------------------------------------------------------------------
  */
@@ -725,7 +725,8 @@ find_indexkey_var(Query *root, RelOptInfo *rel, AttrNumber varattno)
 	{
 		Var		   *var = (Var *) lfirst(temp);
 
-		if (var->varattno == varattno)
+		if (IsA(var, Var) &&
+			var->varattno == varattno)
 			return var;
 	}