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.

src/backend/access/common/heaptuple.c

@@ -9,7 +9,7 @@
  *
  *
  * IDENTIFICATION
- *	  $PostgreSQL: pgsql/src/backend/access/common/heaptuple.c,v 1.91 2004/06/04 20:35:21 tgl Exp $
+ *	  $PostgreSQL: pgsql/src/backend/access/common/heaptuple.c,v 1.92 2004/06/05 01:55:04 tgl Exp $
  *
  * NOTES
  *	  The old interface functions have been converted to macros
@@ -21,6 +21,7 @@
 #include "postgres.h"
 
 #include "access/heapam.h"
+#include "access/tuptoaster.h"
 #include "catalog/pg_type.h"
 
 
@@ -567,8 +568,9 @@ heap_formtuple(TupleDesc tupleDescriptor,
 	unsigned long len;
 	int			hoff;
 	bool		hasnull = false;
-	int			i;
+	Form_pg_attribute *att = tupleDescriptor->attrs;
 	int			numberOfAttributes = tupleDescriptor->natts;
+	int			i;
 
 	if (numberOfAttributes > MaxTupleAttributeNumber)
 		ereport(ERROR,
@@ -577,17 +579,34 @@ heap_formtuple(TupleDesc tupleDescriptor,
 						numberOfAttributes, MaxTupleAttributeNumber)));
 
 	/*
-	 * Determine total space needed
+	 * Check for nulls and embedded tuples; expand any toasted attributes
+	 * in embedded tuples.  This preserves the invariant that toasting can
+	 * only go one level deep.
+	 *
+	 * We can skip calling toast_flatten_tuple_attribute() if the attribute
+	 * couldn't possibly be of composite type.  All composite datums are
+	 * varlena and have alignment 'd'; furthermore they aren't arrays.
+	 * Also, if an attribute is already toasted, it must have been sent to
+	 * disk already and so cannot contain toasted attributes.
 	 */
 	for (i = 0; i < numberOfAttributes; i++)
 	{
 		if (nulls[i] != ' ')
-		{
 			hasnull = true;
-			break;
+		else if (att[i]->attlen == -1 &&
+				 att[i]->attalign == 'd' &&
+				 att[i]->attndims == 0 &&
+				 !VARATT_IS_EXTENDED(values[i]))
+		{
+			values[i] = toast_flatten_tuple_attribute(values[i],
+													  att[i]->atttypid,
+													  att[i]->atttypmod);
 		}
 	}
 
+	/*
+	 * Determine total space needed
+	 */
 	len = offsetof(HeapTupleHeaderData, t_bits);
 
 	if (hasnull)
@@ -744,7 +763,11 @@ heap_deformtuple(HeapTuple tuple,
 	bool		slow = false;	/* can we use/set attcacheoff? */
 
 	natts = tup->t_natts;
-	/* This min() operation is pure paranoia */
+	/*
+	 * In inheritance situations, it is possible that the given tuple actually
+	 * has more fields than the caller is expecting.  Don't run off the end
+	 * of the caller's arrays.
+	 */
 	natts = Min(natts, tdesc_natts);
 
 	tp = (char *) tup + tup->t_hoff;

src/backend/access/heap/tuptoaster.c

@@ -8,7 +8,7 @@
  *
  *
  * IDENTIFICATION
- *	  $PostgreSQL: pgsql/src/backend/access/heap/tuptoaster.c,v 1.42 2004/06/04 20:35:21 tgl Exp $
+ *	  $PostgreSQL: pgsql/src/backend/access/heap/tuptoaster.c,v 1.43 2004/06/05 01:55:04 tgl Exp $
  *
  *
  * INTERFACE ROUTINES
@@ -35,6 +35,7 @@
 #include "utils/builtins.h"
 #include "utils/fmgroids.h"
 #include "utils/pg_lzcompress.h"
+#include "utils/typcache.h"
 
 
 #undef TOAST_DEBUG
@@ -458,10 +459,10 @@ toast_insert_or_update(Relation rel, HeapTuple newtup, HeapTuple oldtup)
 			 * still in the tuple must be someone else's we cannot reuse.
 			 * Expand it to plain (and, probably, toast it again below).
 			 */
-			if (VARATT_IS_EXTERNAL(DatumGetPointer(toast_values[i])))
+			if (VARATT_IS_EXTERNAL(new_value))
 			{
-				toast_values[i] = PointerGetDatum(heap_tuple_untoast_attr(
+				new_value = heap_tuple_untoast_attr(new_value);
-						(varattrib *) DatumGetPointer(toast_values[i])));
+				toast_values[i] = PointerGetDatum(new_value);
 				toast_free[i] = true;
 				need_change = true;
 				need_free = true;
@@ -470,7 +471,7 @@ toast_insert_or_update(Relation rel, HeapTuple newtup, HeapTuple oldtup)
 			/*
 			 * Remember the size of this attribute
 			 */
-			toast_sizes[i] = VARATT_SIZE(DatumGetPointer(toast_values[i]));
+			toast_sizes[i] = VARATT_SIZE(new_value);
 		}
 		else
 		{
@@ -785,6 +786,128 @@ toast_insert_or_update(Relation rel, HeapTuple newtup, HeapTuple oldtup)
 }
 
 
+/* ----------
+ * toast_flatten_tuple_attribute -
+ *
+ *	If a Datum is of composite type, "flatten" it to contain no toasted fields.
+ *	This must be invoked on any potentially-composite field that is to be
+ *	inserted into a tuple.  Doing this preserves the invariant that toasting
+ *	goes only one level deep in a tuple.
+ * ----------
+ */
+Datum
+toast_flatten_tuple_attribute(Datum value,
+							  Oid typeId, int32 typeMod)
+{
+	TupleDesc	tupleDesc;
+	HeapTupleHeader olddata;
+	HeapTupleHeader new_data;
+	int32		new_len;
+	HeapTupleData tmptup;
+	Form_pg_attribute *att;
+	int			numAttrs;
+	int			i;
+	bool		need_change = false;
+	bool		has_nulls = false;
+	Datum		toast_values[MaxTupleAttributeNumber];
+	char		toast_nulls[MaxTupleAttributeNumber];
+	bool		toast_free[MaxTupleAttributeNumber];
+
+	/*
+	 * See if it's a composite type, and get the tupdesc if so.
+	 */
+	tupleDesc = lookup_rowtype_tupdesc_noerror(typeId, typeMod, true);
+	if (tupleDesc == NULL)
+		return value;			/* not a composite type */
+
+	att = tupleDesc->attrs;
+	numAttrs = tupleDesc->natts;
+
+	/*
+	 * Break down the tuple into fields.
+	 */
+	olddata = DatumGetHeapTupleHeader(value);
+	Assert(typeId == HeapTupleHeaderGetTypeId(olddata));
+	Assert(typeMod == HeapTupleHeaderGetTypMod(olddata));
+	/* Build a temporary HeapTuple control structure */
+	tmptup.t_len = HeapTupleHeaderGetDatumLength(olddata);
+	ItemPointerSetInvalid(&(tmptup.t_self));
+	tmptup.t_tableOid = InvalidOid;
+	tmptup.t_data = olddata;
+
+	Assert(numAttrs <= MaxTupleAttributeNumber);
+	heap_deformtuple(&tmptup, tupleDesc, toast_values, toast_nulls);
+
+	memset(toast_free, 0, numAttrs * sizeof(bool));
+
+	for (i = 0; i < numAttrs; i++)
+	{
+		/*
+		 * Look at non-null varlena attributes
+		 */
+		if (toast_nulls[i] == 'n')
+			has_nulls = true;
+		else if (att[i]->attlen == -1)
+		{
+			varattrib  *new_value;
+
+			new_value = (varattrib *) DatumGetPointer(toast_values[i]);
+			if (VARATT_IS_EXTENDED(new_value))
+			{
+				new_value = heap_tuple_untoast_attr(new_value);
+				toast_values[i] = PointerGetDatum(new_value);
+				toast_free[i] = true;
+				need_change = true;
+			}
+		}
+	}
+
+	/*
+	 * If nothing to untoast, just return the original tuple.
+	 */
+	if (!need_change)
+		return value;
+
+	/*
+	 * Calculate the new size of the tuple.  Header size should not
+	 * change, but data size might.
+	 */
+	new_len = offsetof(HeapTupleHeaderData, t_bits);
+	if (has_nulls)
+		new_len += BITMAPLEN(numAttrs);
+	if (olddata->t_infomask & HEAP_HASOID)
+		new_len += sizeof(Oid);
+	new_len = MAXALIGN(new_len);
+	Assert(new_len == olddata->t_hoff);
+	new_len += ComputeDataSize(tupleDesc, toast_values, toast_nulls);
+
+	new_data = (HeapTupleHeader) palloc0(new_len);
+
+	/*
+	 * Put the tuple header and the changed values into place
+	 */
+	memcpy(new_data, olddata, olddata->t_hoff);
+
+	HeapTupleHeaderSetDatumLength(new_data, new_len);
+
+	DataFill((char *) new_data + olddata->t_hoff,
+			 tupleDesc,
+			 toast_values,
+			 toast_nulls,
+			 &(new_data->t_infomask),
+			 has_nulls ? new_data->t_bits : NULL);
+
+	/*
+	 * Free allocated temp values
+	 */
+	for (i = 0; i < numAttrs; i++)
+		if (toast_free[i])
+			pfree(DatumGetPointer(toast_values[i]));
+
+	return PointerGetDatum(new_data);
+}
+
+
 /* ----------
  * toast_compress_datum -
  *

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])
+			if (IsA(parentvar, Var) && IsA(childvar, Var))
-				rel->attr_widths[parentndx] = childrel->attr_widths[childndx];
+			{
+				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];
+			}
 		}
 	}
 

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

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;
 	}
 

src/backend/optimizer/prep/prepunion.c

@@ -14,13 +14,14 @@
  *
  *
  * IDENTIFICATION
- *	  $PostgreSQL: pgsql/src/backend/optimizer/prep/prepunion.c,v 1.112 2004/05/30 23:40:29 neilc Exp $
+ *	  $PostgreSQL: pgsql/src/backend/optimizer/prep/prepunion.c,v 1.113 2004/06/05 01:55:04 tgl Exp $
  *
  *-------------------------------------------------------------------------
  */
 #include "postgres.h"
 
 
+#include "access/heapam.h"
 #include "catalog/pg_type.h"
 #include "nodes/makefuncs.h"
 #include "optimizer/clauses.h"
@@ -39,8 +40,10 @@ typedef struct
 {
 	Index		old_rt_index;
 	Index		new_rt_index;
-	Oid			old_relid;
+	TupleDesc	old_tupdesc;
-	Oid			new_relid;
+	TupleDesc	new_tupdesc;
+	char	   *old_rel_name;
+	char	   *new_rel_name;
 } adjust_inherited_attrs_context;
 
 static Plan *recurse_set_operations(Node *setOp, Query *parse,
@@ -65,7 +68,8 @@ static bool tlist_same_datatypes(List *tlist, List *colTypes, bool junkOK);
 static Node *adjust_inherited_attrs_mutator(Node *node,
 							   adjust_inherited_attrs_context *context);
 static Relids adjust_relid_set(Relids relids, Index oldrelid, Index newrelid);
-static List *adjust_inherited_tlist(List *tlist, Oid old_relid, Oid new_relid);
+static List *adjust_inherited_tlist(List *tlist,
+									adjust_inherited_attrs_context *context);
 
 
 /*
@@ -787,17 +791,17 @@ expand_inherited_rtentry(Query *parse, Index rti, bool dup_parent)
  * We also adjust varattno to match the new table by column name, rather
  * than column number.	This hack makes it possible for child tables to have
  * different column positions for the "same" attribute as a parent, which
- * helps ALTER TABLE ADD COLUMN.  Unfortunately this isn't nearly enough to
+ * is necessary for ALTER TABLE ADD COLUMN.
- * make it work transparently; there are other places where things fall down
- * if children and parents don't have the same column numbers for inherited
- * attributes.	It'd be better to rip this code out and fix ALTER TABLE...
  */
 Node *
 adjust_inherited_attrs(Node *node,
 					   Index old_rt_index, Oid old_relid,
 					   Index new_rt_index, Oid new_relid)
 {
+	Node	   *result;
 	adjust_inherited_attrs_context context;
+	Relation	oldrelation;
+	Relation	newrelation;
 
 	/* Handle simple case simply... */
 	if (old_rt_index == new_rt_index)
@@ -806,10 +810,19 @@ adjust_inherited_attrs(Node *node,
 		return copyObject(node);
 	}
 
+	/*
+	 * We assume that by now the planner has acquired at least AccessShareLock
+	 * on both rels, and so we need no additional lock now.
+	 */
+	oldrelation = heap_open(old_relid, NoLock);
+	newrelation = heap_open(new_relid, NoLock);
+
 	context.old_rt_index = old_rt_index;
 	context.new_rt_index = new_rt_index;
-	context.old_relid = old_relid;
+	context.old_tupdesc = RelationGetDescr(oldrelation);
-	context.new_relid = new_relid;
+	context.new_tupdesc = RelationGetDescr(newrelation);
+	context.old_rel_name = RelationGetRelationName(oldrelation);
+	context.new_rel_name = RelationGetRelationName(newrelation);
 
 	/*
 	 * Must be prepared to start with a Query or a bare expression tree.
@@ -829,13 +842,109 @@ adjust_inherited_attrs(Node *node,
 			if (newnode->commandType == CMD_UPDATE)
 				newnode->targetList =
 					adjust_inherited_tlist(newnode->targetList,
-										   old_relid,
+										   &context);
-										   new_relid);
 		}
-		return (Node *) newnode;
+		result = (Node *) newnode;
 	}
 	else
-		return adjust_inherited_attrs_mutator(node, &context);
+		result = adjust_inherited_attrs_mutator(node, &context);
+
+	heap_close(oldrelation, NoLock);
+	heap_close(newrelation, NoLock);
+
+	return result;
+}
+
+/*
+ * Translate parent's attribute number into child's.
+ *
+ * For paranoia's sake, we match type as well as attribute name.
+ */
+static AttrNumber
+translate_inherited_attnum(AttrNumber old_attno,
+						   adjust_inherited_attrs_context *context)
+{
+	Form_pg_attribute att;
+	char	   *attname;
+	Oid			atttypid;
+	int32		atttypmod;
+	int			newnatts;
+	int			i;
+
+	if (old_attno <= 0 || old_attno > context->old_tupdesc->natts)
+		elog(ERROR, "attribute %d of relation \"%s\" does not exist",
+			 (int) old_attno, context->old_rel_name);
+	att = context->old_tupdesc->attrs[old_attno - 1];
+	if (att->attisdropped)
+		elog(ERROR, "attribute %d of relation \"%s\" does not exist",
+			 (int) old_attno, context->old_rel_name);
+	attname = NameStr(att->attname);
+	atttypid = att->atttypid;
+	atttypmod = att->atttypmod;
+
+	newnatts = context->new_tupdesc->natts;
+	for (i = 0; i < newnatts; i++)
+	{
+		att = context->new_tupdesc->attrs[i];
+		if (att->attisdropped)
+			continue;
+		if (strcmp(attname, NameStr(att->attname)) == 0)
+		{
+			/* Found it, check type */
+			if (atttypid != att->atttypid || atttypmod != att->atttypmod)
+				elog(ERROR, "attribute \"%s\" of relation \"%s\" does not match parent's type",
+					 attname, context->new_rel_name);
+			return (AttrNumber) (i + 1);
+		}
+	}
+
+	elog(ERROR, "attribute \"%s\" of relation \"%s\" does not exist",
+		 attname, context->new_rel_name);
+	return 0;					/* keep compiler quiet */
+}
+
+/*
+ * Translate a whole-row Var to be correct for a child table.
+ *
+ * In general the child will not have a suitable field layout to be used
+ * directly, so we translate the simple whole-row Var into a ROW() construct.
+ */
+static Node *
+generate_whole_row(Var *var,
+				   adjust_inherited_attrs_context *context)
+{
+	RowExpr		*rowexpr;
+	List		*fields = NIL;
+	int			oldnatts = context->old_tupdesc->natts;
+	int			i;
+
+	for (i = 0; i < oldnatts; i++)
+	{
+		Form_pg_attribute att = context->old_tupdesc->attrs[i];
+		Var		*newvar;
+
+		if (att->attisdropped)
+		{
+			/*
+			 * can't use atttypid here, but it doesn't really matter
+			 * what type the Const claims to be.
+			 */
+			newvar = (Var *) makeNullConst(INT4OID);
+		}
+		else
+			newvar = makeVar(context->new_rt_index,
+							 translate_inherited_attnum(i + 1, context),
+							 att->atttypid,
+							 att->atttypmod,
+							 0);
+		fields = lappend(fields, newvar);
+	}
+	rowexpr = makeNode(RowExpr);
+	rowexpr->args = fields;
+	rowexpr->row_typeid = var->vartype;	/* report parent's rowtype */
+	rowexpr->row_format = COERCE_IMPLICIT_CAST;
+
+	return (Node *) rowexpr;
 }
 
 static Node *
@@ -855,17 +964,16 @@ adjust_inherited_attrs_mutator(Node *node,
 			var->varnoold = context->new_rt_index;
 			if (var->varattno > 0)
 			{
-				char	   *attname;
+				var->varattno = translate_inherited_attnum(var->varattno,
-
+														   context);
-				attname = get_relid_attribute_name(context->old_relid,
-												   var->varattno);
-				var->varattno = get_attnum(context->new_relid, attname);
-				if (var->varattno == InvalidAttrNumber)
-					elog(ERROR, "attribute \"%s\" of relation \"%s\" does not exist",
-						 attname, get_rel_name(context->new_relid));
 				var->varoattno = var->varattno;
-				pfree(attname);
 			}
+			else if (var->varattno == 0)
+			{
+				/* expand whole-row reference into a ROW() construct */
+				return generate_whole_row(var, context);
+			}
+			/* system attributes don't need any translation */
 		}
 		return (Node *) var;
 	}
@@ -1022,7 +1130,8 @@ adjust_relid_set(Relids relids, Index oldrelid, Index newrelid)
  * Note that this is not needed for INSERT because INSERT isn't inheritable.
  */
 static List *
-adjust_inherited_tlist(List *tlist, Oid old_relid, Oid new_relid)
+adjust_inherited_tlist(List *tlist,
+					   adjust_inherited_attrs_context *context)
 {
 	bool		changed_it = false;
 	ListCell   *tl;
@@ -1035,26 +1144,19 @@ adjust_inherited_tlist(List *tlist, Oid old_relid, Oid new_relid)
 	{
 		TargetEntry *tle = (TargetEntry *) lfirst(tl);
 		Resdom	   *resdom = tle->resdom;
-		char	   *attname;
 
 		if (resdom->resjunk)
 			continue;			/* ignore junk items */
 
-		attname = get_relid_attribute_name(old_relid, resdom->resno);
+		attrno = translate_inherited_attnum(resdom->resno, context);
-		attrno = get_attnum(new_relid, attname);
+
-		if (attrno == InvalidAttrNumber)
-			elog(ERROR, "attribute \"%s\" of relation \"%s\" does not exist",
-				 attname, get_rel_name(new_relid));
 		if (resdom->resno != attrno)
 		{
 			resdom = (Resdom *) copyObject((Node *) resdom);
 			resdom->resno = attrno;
-			resdom->resname = attname;
 			tle->resdom = resdom;
 			changed_it = true;
 		}
-		else
-			pfree(attname);
 	}
 
 	/*

src/backend/optimizer/util/relnode.c

@@ -8,7 +8,7 @@
  *
  *
  * IDENTIFICATION
- *	  $PostgreSQL: pgsql/src/backend/optimizer/util/relnode.c,v 1.59 2004/06/01 03:03:02 tgl Exp $
+ *	  $PostgreSQL: pgsql/src/backend/optimizer/util/relnode.c,v 1.60 2004/06/05 01:55:05 tgl Exp $
  *
  *-------------------------------------------------------------------------
  */
@@ -381,6 +381,9 @@ build_joinrel_tlist(Query *root, RelOptInfo *joinrel)
 			Var		   *var = (Var *) lfirst(vars);
 			int			ndx = var->varattno - baserel->min_attr;
 
+			/* We can't run into any child RowExprs here */
+			Assert(IsA(var, Var));
+
 			if (bms_nonempty_difference(baserel->attr_needed[ndx], relids))
 			{
 				joinrel->reltargetlist = lappend(joinrel->reltargetlist, var);

src/backend/optimizer/util/tlist.c

@@ -8,7 +8,7 @@
  *
  *
  * IDENTIFICATION
- *	  $PostgreSQL: pgsql/src/backend/optimizer/util/tlist.c,v 1.64 2004/05/30 23:40:31 neilc Exp $
+ *	  $PostgreSQL: pgsql/src/backend/optimizer/util/tlist.c,v 1.65 2004/06/05 01:55:05 tgl Exp $
  *
  *-------------------------------------------------------------------------
  */
@@ -17,6 +17,7 @@
 #include "nodes/makefuncs.h"
 #include "optimizer/tlist.h"
 #include "optimizer/var.h"
+#include "parser/parse_expr.h"
 
 
 /*****************************************************************************
@@ -83,13 +84,28 @@ tlist_member(Node *node, List *targetlist)
  * create_tl_element
  *	  Creates a target list entry node and its associated (resdom var) pair
  *	  with its resdom number equal to 'resdomno'.
+ *
+ * Note: the argument is almost always a Var, but occasionally not.
  */
 TargetEntry *
 create_tl_element(Var *var, int resdomno)
 {
+	Oid		vartype;
+	int32	vartypmod;
+
+	if (IsA(var, Var))
+	{
+		vartype = var->vartype;
+		vartypmod = var->vartypmod;
+	}
+	else
+	{
+		vartype = exprType((Node *) var);
+		vartypmod = exprTypmod((Node *) var);
+	}
 	return makeTargetEntry(makeResdom(resdomno,
-									  var->vartype,
+									  vartype,
-									  var->vartypmod,
+									  vartypmod,
 									  NULL,
 									  false),
 						   (Expr *) var);

src/backend/utils/cache/typcache.c

@@ -36,7 +36,7 @@
  * Portions Copyright (c) 1994, Regents of the University of California
  *
  * IDENTIFICATION
- *	  $PostgreSQL: pgsql/src/backend/utils/cache/typcache.c,v 1.6 2004/05/26 04:41:40 neilc Exp $
+ *	  $PostgreSQL: pgsql/src/backend/utils/cache/typcache.c,v 1.7 2004/06/05 01:55:05 tgl Exp $
  *
  *-------------------------------------------------------------------------
  */
@@ -384,6 +384,19 @@ lookup_default_opclass(Oid type_id, Oid am_id)
  */
 TupleDesc
 lookup_rowtype_tupdesc(Oid type_id, int32 typmod)
+{
+	return lookup_rowtype_tupdesc_noerror(type_id, typmod, false);
+}
+
+/*
+ * lookup_rowtype_tupdesc_noerror
+ *
+ * As above, but if the type is not a known composite type and noError
+ * is true, returns NULL instead of ereport'ing.  (Note that if a bogus
+ * type_id is passed, you'll get an ereport anyway.)
+ */
+TupleDesc
+lookup_rowtype_tupdesc_noerror(Oid type_id, int32 typmod, bool noError)
 {
 	if (type_id != RECORDOID)
 	{
@@ -393,8 +406,7 @@ lookup_rowtype_tupdesc(Oid type_id, int32 typmod)
 		TypeCacheEntry *typentry;
 
 		typentry = lookup_type_cache(type_id, TYPECACHE_TUPDESC);
-		/* this should not happen unless caller messed up: */
+		if (typentry->tupDesc == NULL && !noError)
-		if (typentry->tupDesc == NULL)
 			ereport(ERROR,
 					(errcode(ERRCODE_WRONG_OBJECT_TYPE),
 					 errmsg("type %u is not composite",
@@ -408,9 +420,11 @@ lookup_rowtype_tupdesc(Oid type_id, int32 typmod)
 		 */
 		if (typmod < 0 || typmod >= NextRecordTypmod)
 		{
-			ereport(ERROR,
+			if (!noError)
-					(errcode(ERRCODE_WRONG_OBJECT_TYPE),
+				ereport(ERROR,
-					 errmsg("record type has not been registered")));
+						(errcode(ERRCODE_WRONG_OBJECT_TYPE),
+						 errmsg("record type has not been registered")));
+			return NULL;
 		}
 		return RecordCacheArray[typmod];
 	}

src/include/access/tuptoaster.h

@@ -6,7 +6,7 @@
  *
  * Copyright (c) 2000-2003, PostgreSQL Global Development Group
  *
- * $PostgreSQL: pgsql/src/include/access/tuptoaster.h,v 1.17 2003/11/29 22:40:55 pgsql Exp $
+ * $PostgreSQL: pgsql/src/include/access/tuptoaster.h,v 1.18 2004/06/05 01:55:05 tgl Exp $
  *
  *-------------------------------------------------------------------------
  */
@@ -110,6 +110,18 @@ extern varattrib *heap_tuple_untoast_attr_slice(varattrib *attr,
 							  int32 sliceoffset,
 							  int32 slicelength);
 
+/* ----------
+ * toast_flatten_tuple_attribute -
+ *
+ *	If a Datum is of composite type, "flatten" it to contain no toasted fields.
+ *	This must be invoked on any potentially-composite field that is to be
+ *	inserted into a tuple.  Doing this preserves the invariant that toasting
+ *	goes only one level deep in a tuple.
+ * ----------
+ */
+extern Datum toast_flatten_tuple_attribute(Datum value,
+										   Oid typeId, int32 typeMod);
+
 /* ----------
  * toast_compress_datum -
  *

src/include/nodes/relation.h

@@ -7,7 +7,7 @@
  * Portions Copyright (c) 1996-2003, PostgreSQL Global Development Group
  * Portions Copyright (c) 1994, Regents of the University of California
  *
- * $PostgreSQL: pgsql/src/include/nodes/relation.h,v 1.95 2004/06/01 03:03:05 tgl Exp $
+ * $PostgreSQL: pgsql/src/include/nodes/relation.h,v 1.96 2004/06/05 01:55:05 tgl Exp $
  *
  *-------------------------------------------------------------------------
  */
@@ -91,6 +91,7 @@ typedef struct QualCost
  *				appropriate projections have been done (ie, output width)
  *		reltargetlist - List of Var nodes for the attributes we need to
  *						output from this relation (in no particular order)
+ *						NOTE: in a child relation, may contain RowExprs
  *		pathlist - List of Path nodes, one for each potentially useful
  *				   method of generating the relation
  *		cheapest_startup_path - the pathlist member with lowest startup cost

src/include/utils/typcache.h

@@ -9,7 +9,7 @@
  * Portions Copyright (c) 1996-2003, PostgreSQL Global Development Group
  * Portions Copyright (c) 1994, Regents of the University of California
  *
- * $PostgreSQL: pgsql/src/include/utils/typcache.h,v 1.3 2004/04/01 21:28:46 tgl Exp $
+ * $PostgreSQL: pgsql/src/include/utils/typcache.h,v 1.4 2004/06/05 01:55:05 tgl Exp $
  *
  *-------------------------------------------------------------------------
  */
@@ -76,6 +76,9 @@ extern TypeCacheEntry *lookup_type_cache(Oid type_id, int flags);
 
 extern TupleDesc lookup_rowtype_tupdesc(Oid type_id, int32 typmod);
 
+extern TupleDesc lookup_rowtype_tupdesc_noerror(Oid type_id, int32 typmod,
+												bool noError);
+
 extern void assign_record_type_typmod(TupleDesc tupDesc);
 
 extern void flush_rowtype_cache(Oid type_id);