Instead of supposing (wrongly, in the general case) that the rowtype

of an inheritance child table is binary-compatible with the rowtype of
its parent, invent an expression node type that does the conversion
correctly.  Fixes the new bug exhibited by Kris Shannon as well as a
lot of old bugs that would only show up when using multiple inheritance
or after altering the parent table.

src/backend/executor/execQual.c

@@ -8,7 +8,7 @@
  *
  *
  * IDENTIFICATION
- *	  $PostgreSQL: pgsql/src/backend/executor/execQual.c,v 1.169 2004/09/22 17:41:50 tgl Exp $
+ *	  $PostgreSQL: pgsql/src/backend/executor/execQual.c,v 1.170 2004/12/11 23:26:29 tgl Exp $
  *
  *-------------------------------------------------------------------------
  */
@@ -87,6 +87,9 @@ static Datum ExecEvalOr(BoolExprState *orExpr, ExprContext *econtext,
 		   bool *isNull, ExprDoneCond *isDone);
 static Datum ExecEvalAnd(BoolExprState *andExpr, ExprContext *econtext,
 			bool *isNull, ExprDoneCond *isDone);
+static Datum ExecEvalConvertRowtype(ConvertRowtypeExprState *cstate,
+									ExprContext *econtext,
+									bool *isNull, ExprDoneCond *isDone);
 static Datum ExecEvalCase(CaseExprState *caseExpr, ExprContext *econtext,
 			 bool *isNull, ExprDoneCond *isDone);
 static Datum ExecEvalCaseTestExpr(ExprState *exprstate,
@@ -428,7 +431,8 @@ ExecEvalAggref(AggrefExprState *aggref, ExprContext *econtext,
  *
  *		Returns a Datum whose value is the value of a range
  *		variable with respect to given expression context.
- * ---------------------------------------------------------------- */
+ * ----------------------------------------------------------------
+ */
 static Datum
 ExecEvalVar(ExprState *exprstate, ExprContext *econtext,
 			bool *isNull, ExprDoneCond *isDone)
@@ -1844,6 +1848,75 @@ ExecEvalAnd(BoolExprState *andExpr, ExprContext *econtext,
 	return BoolGetDatum(!AnyNull);
 }
 
+/* ----------------------------------------------------------------
+ *		ExecEvalConvertRowtype
+ *
+ *		Evaluate a rowtype coercion operation.  This may require
+ *		rearranging field positions.
+ * ----------------------------------------------------------------
+ */
+static Datum
+ExecEvalConvertRowtype(ConvertRowtypeExprState *cstate,
+					   ExprContext *econtext,
+					   bool *isNull, ExprDoneCond *isDone)
+{
+	HeapTuple	result;
+	Datum		tupDatum;
+	HeapTupleHeader tuple;
+	HeapTupleData tmptup;
+	AttrNumber *attrMap = cstate->attrMap;
+	Datum	   *invalues = cstate->invalues;
+	char	   *innulls = cstate->innulls;
+	Datum	   *outvalues = cstate->outvalues;
+	char	   *outnulls = cstate->outnulls;
+	int			i;
+	int			outnatts = cstate->outdesc->natts;
+
+	tupDatum = ExecEvalExpr(cstate->arg, econtext, isNull, isDone);
+
+	/* this test covers the isDone exception too: */
+	if (*isNull)
+		return tupDatum;
+
+	tuple = DatumGetHeapTupleHeader(tupDatum);
+
+	Assert(HeapTupleHeaderGetTypeId(tuple) == cstate->indesc->tdtypeid);
+	Assert(HeapTupleHeaderGetTypMod(tuple) == cstate->indesc->tdtypmod);
+
+	/*
+	 * heap_deformtuple needs a HeapTuple not a bare HeapTupleHeader.
+	 */
+	tmptup.t_len = HeapTupleHeaderGetDatumLength(tuple);
+	tmptup.t_data = tuple;
+
+	/*
+	 * Extract all the values of the old tuple, offsetting the arrays
+	 * so that invalues[0] is NULL and invalues[1] is the first
+	 * source attribute; this exactly matches the numbering convention
+	 * in attrMap.
+	 */
+	heap_deformtuple(&tmptup, cstate->indesc, invalues + 1, innulls + 1);
+	invalues[0] = (Datum) 0;
+	innulls[0] = 'n';
+
+	/*
+	 * Transpose into proper fields of the new tuple.
+	 */
+	for (i = 0; i < outnatts; i++)
+	{
+		int			j = attrMap[i];
+
+		outvalues[i] = invalues[j];
+		outnulls[i] = innulls[j];
+	}
+
+	/*
+	 * Now form the new tuple.
+	 */
+	result = heap_formtuple(cstate->outdesc, outvalues, outnulls);
+
+	return HeapTupleGetDatum(result);
+}
 
 /* ----------------------------------------------------------------
  *		ExecEvalCase
@@ -2969,6 +3042,68 @@ ExecInitExpr(Expr *node, PlanState *parent)
 				state = (ExprState *) gstate;
 			}
 			break;
+		case T_ConvertRowtypeExpr:
+			{
+				ConvertRowtypeExpr *convert = (ConvertRowtypeExpr *) node;
+				ConvertRowtypeExprState *cstate = makeNode(ConvertRowtypeExprState);
+				int		i;
+				int		n;
+
+				cstate->xprstate.evalfunc = (ExprStateEvalFunc) ExecEvalConvertRowtype;
+				cstate->arg = ExecInitExpr(convert->arg, parent);
+				/* save copies of needed tuple descriptors */
+				cstate->indesc = lookup_rowtype_tupdesc(exprType((Node *) convert->arg), -1);
+				cstate->indesc = CreateTupleDescCopy(cstate->indesc);
+				cstate->outdesc = lookup_rowtype_tupdesc(convert->resulttype, -1);
+				cstate->outdesc = CreateTupleDescCopy(cstate->outdesc);
+				/* prepare map from old to new attribute numbers */
+				n = cstate->outdesc->natts;
+				cstate->attrMap = (AttrNumber *) palloc0(n * sizeof(AttrNumber));
+				for (i = 0; i < n; i++)
+				{
+					Form_pg_attribute att = cstate->outdesc->attrs[i];
+					char	   *attname;
+					Oid			atttypid;
+					int32		atttypmod;
+					int			j;
+
+					if (att->attisdropped)
+						continue;	/* attrMap[i] is already 0 */
+					attname = NameStr(att->attname);
+					atttypid = att->atttypid;
+					atttypmod = att->atttypmod;
+					for (j = 0; j < cstate->indesc->natts; j++)
+					{
+						att = cstate->indesc->attrs[j];
+						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 type %s does not match corresponding attribute of type %s",
+									 attname,
+									 format_type_be(cstate->indesc->tdtypeid),
+									 format_type_be(cstate->outdesc->tdtypeid));
+							cstate->attrMap[i] = (AttrNumber) (j + 1);
+							break;
+						}
+					}
+					if (cstate->attrMap[i] == 0)
+						elog(ERROR, "attribute \"%s\" of type %s does not exist",
+							 attname,
+							 format_type_be(cstate->indesc->tdtypeid));
+				}
+				/* preallocate workspace for Datum arrays */
+				n = cstate->indesc->natts + 1;	/* +1 for NULL */
+				cstate->invalues = (Datum *) palloc(n * sizeof(Datum));
+				cstate->innulls = (char *) palloc(n * sizeof(char));
+				n = cstate->outdesc->natts;
+				cstate->outvalues = (Datum *) palloc(n * sizeof(Datum));
+				cstate->outnulls = (char *) palloc(n * sizeof(char));
+				state = (ExprState *) cstate;
+			}
+			break;
 		case T_CaseExpr:
 			{
 				CaseExpr   *caseexpr = (CaseExpr *) node;

src/backend/nodes/copyfuncs.c

@@ -15,7 +15,7 @@
  * Portions Copyright (c) 1994, Regents of the University of California
  *
  * IDENTIFICATION
- *	  $PostgreSQL: pgsql/src/backend/nodes/copyfuncs.c,v 1.293 2004/11/05 19:15:59 tgl Exp $
+ *	  $PostgreSQL: pgsql/src/backend/nodes/copyfuncs.c,v 1.294 2004/12/11 23:26:33 tgl Exp $
  *
  *-------------------------------------------------------------------------
  */
@@ -876,6 +876,21 @@ _copyRelabelType(RelabelType *from)
 	return newnode;
 }
 
+/*
+ * _copyConvertRowtypeExpr
+ */
+static ConvertRowtypeExpr *
+_copyConvertRowtypeExpr(ConvertRowtypeExpr *from)
+{
+	ConvertRowtypeExpr *newnode = makeNode(ConvertRowtypeExpr);
+
+	COPY_NODE_FIELD(arg);
+	COPY_SCALAR_FIELD(resulttype);
+	COPY_SCALAR_FIELD(convertformat);
+
+	return newnode;
+}
+
 /*
  * _copyCaseExpr
  */
@@ -2696,6 +2711,9 @@ copyObject(void *from)
 		case T_RelabelType:
 			retval = _copyRelabelType(from);
 			break;
+		case T_ConvertRowtypeExpr:
+			retval = _copyConvertRowtypeExpr(from);
+			break;
 		case T_CaseExpr:
 			retval = _copyCaseExpr(from);
 			break;

src/backend/nodes/equalfuncs.c

@@ -18,7 +18,7 @@
  * Portions Copyright (c) 1994, Regents of the University of California
  *
  * IDENTIFICATION
- *	  $PostgreSQL: pgsql/src/backend/nodes/equalfuncs.c,v 1.232 2004/11/05 19:15:59 tgl Exp $
+ *	  $PostgreSQL: pgsql/src/backend/nodes/equalfuncs.c,v 1.233 2004/12/11 23:26:33 tgl Exp $
  *
  *-------------------------------------------------------------------------
  */
@@ -380,6 +380,24 @@ _equalRelabelType(RelabelType *a, RelabelType *b)
 	return true;
 }
 
+static bool
+_equalConvertRowtypeExpr(ConvertRowtypeExpr *a, ConvertRowtypeExpr *b)
+{
+	COMPARE_NODE_FIELD(arg);
+	COMPARE_SCALAR_FIELD(resulttype);
+
+	/*
+	 * Special-case COERCE_DONTCARE, so that planner can build coercion
+	 * nodes that are equal() to both explicit and implicit coercions.
+	 */
+	if (a->convertformat != b->convertformat &&
+		a->convertformat != COERCE_DONTCARE &&
+		b->convertformat != COERCE_DONTCARE)
+		return false;
+
+	return true;
+}
+
 static bool
 _equalCaseExpr(CaseExpr *a, CaseExpr *b)
 {
@@ -1844,6 +1862,9 @@ equal(void *a, void *b)
 		case T_RelabelType:
 			retval = _equalRelabelType(a, b);
 			break;
+		case T_ConvertRowtypeExpr:
+			retval = _equalConvertRowtypeExpr(a, b);
+			break;
 		case T_CaseExpr:
 			retval = _equalCaseExpr(a, b);
 			break;

src/backend/nodes/outfuncs.c

@@ -8,7 +8,7 @@
  *
  *
  * IDENTIFICATION
- *	  $PostgreSQL: pgsql/src/backend/nodes/outfuncs.c,v 1.243 2004/08/29 05:06:43 momjian Exp $
+ *	  $PostgreSQL: pgsql/src/backend/nodes/outfuncs.c,v 1.244 2004/12/11 23:26:33 tgl Exp $
  *
  * NOTES
  *	  Every node type that can appear in stored rules' parsetrees *must*
@@ -767,6 +767,16 @@ _outRelabelType(StringInfo str, RelabelType *node)
 	WRITE_ENUM_FIELD(relabelformat, CoercionForm);
 }
 
+static void
+_outConvertRowtypeExpr(StringInfo str, ConvertRowtypeExpr *node)
+{
+	WRITE_NODE_TYPE("CONVERTROWTYPEEXPR");
+
+	WRITE_NODE_FIELD(arg);
+	WRITE_OID_FIELD(resulttype);
+	WRITE_ENUM_FIELD(convertformat, CoercionForm);
+}
+
 static void
 _outCaseExpr(StringInfo str, CaseExpr *node)
 {
@@ -1728,6 +1738,9 @@ _outNode(StringInfo str, void *obj)
 			case T_RelabelType:
 				_outRelabelType(str, obj);
 				break;
+			case T_ConvertRowtypeExpr:
+				_outConvertRowtypeExpr(str, obj);
+				break;
 			case T_CaseExpr:
 				_outCaseExpr(str, obj);
 				break;

src/backend/nodes/readfuncs.c

@@ -8,7 +8,7 @@
  *
  *
  * IDENTIFICATION
- *	  $PostgreSQL: pgsql/src/backend/nodes/readfuncs.c,v 1.173 2004/08/29 04:12:33 momjian Exp $
+ *	  $PostgreSQL: pgsql/src/backend/nodes/readfuncs.c,v 1.174 2004/12/11 23:26:34 tgl Exp $
  *
  * NOTES
  *	  Path and Plan nodes do not have any readfuncs support, because we
@@ -575,6 +575,21 @@ _readRelabelType(void)
 	READ_DONE();
 }
 
+/*
+ * _readConvertRowtypeExpr
+ */
+static ConvertRowtypeExpr *
+_readConvertRowtypeExpr(void)
+{
+	READ_LOCALS(ConvertRowtypeExpr);
+
+	READ_NODE_FIELD(arg);
+	READ_OID_FIELD(resulttype);
+	READ_ENUM_FIELD(convertformat, CoercionForm);
+
+	READ_DONE();
+}
+
 /*
  * _readCaseExpr
  */
@@ -971,6 +986,8 @@ parseNodeString(void)
 		return_value = _readFieldStore();
 	else if (MATCH("RELABELTYPE", 11))
 		return_value = _readRelabelType();
+	else if (MATCH("CONVERTROWTYPEEXPR", 18))
+		return_value = _readConvertRowtypeExpr();
 	else if (MATCH("CASE", 4))
 		return_value = _readCaseExpr();
 	else if (MATCH("WHEN", 4))

src/backend/optimizer/prep/prepjointree.c

@@ -16,7 +16,7 @@
  *
  *
  * IDENTIFICATION
- *	  $PostgreSQL: pgsql/src/backend/optimizer/prep/prepjointree.c,v 1.23 2004/08/29 05:06:44 momjian Exp $
+ *	  $PostgreSQL: pgsql/src/backend/optimizer/prep/prepjointree.c,v 1.24 2004/12/11 23:26:37 tgl Exp $
  *
  *-------------------------------------------------------------------------
  */
@@ -839,6 +839,13 @@ find_nonnullable_rels(Node *node, bool top_level)
 
 		result = find_nonnullable_rels((Node *) expr->arg, top_level);
 	}
+	else if (IsA(node, ConvertRowtypeExpr))
+	{
+		/* not clear this is useful, but it can't hurt */
+		ConvertRowtypeExpr *expr = (ConvertRowtypeExpr *) node;
+
+		result = find_nonnullable_rels((Node *) expr->arg, top_level);
+	}
 	else if (IsA(node, NullTest))
 	{
 		NullTest   *expr = (NullTest *) node;

src/backend/optimizer/prep/prepunion.c

@@ -14,7 +14,7 @@
  *
  *
  * IDENTIFICATION
- *	  $PostgreSQL: pgsql/src/backend/optimizer/prep/prepunion.c,v 1.117 2004/10/02 22:39:47 tgl Exp $
+ *	  $PostgreSQL: pgsql/src/backend/optimizer/prep/prepunion.c,v 1.118 2004/12/11 23:26:37 tgl Exp $
  *
  *-------------------------------------------------------------------------
  */
@@ -40,6 +40,8 @@ typedef struct
 {
 	Index		old_rt_index;
 	Index		new_rt_index;
+	Oid			old_rel_type;
+	Oid			new_rel_type;
 	TupleDesc	old_tupdesc;
 	TupleDesc	new_tupdesc;
 	char	   *old_rel_name;
@@ -826,6 +828,8 @@ adjust_inherited_attrs(Node *node,
 
 	context.old_rt_index = old_rt_index;
 	context.new_rt_index = new_rt_index;
+	context.old_rel_type = oldrelation->rd_rel->reltype;
+	context.new_rel_type = newrelation->rd_rel->reltype;
 	context.old_tupdesc = RelationGetDescr(oldrelation);
 	context.new_tupdesc = RelationGetDescr(newrelation);
 	context.old_rel_name = RelationGetRelationName(oldrelation);
@@ -910,50 +914,6 @@ translate_inherited_attnum(AttrNumber old_attno,
 	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 *
 adjust_inherited_attrs_mutator(Node *node,
 							   adjust_inherited_attrs_context *context)
@@ -977,8 +937,22 @@ adjust_inherited_attrs_mutator(Node *node,
 			}
 			else if (var->varattno == 0)
 			{
-				/* expand whole-row reference into a ROW() construct */
-				return generate_whole_row(var, context);
+				/*
+				 * Whole-row Var: we need to insert a coercion step to convert
+				 * the tuple layout to the parent's rowtype.
+				 */
+				if (context->old_rel_type != context->new_rel_type)
+				{
+					ConvertRowtypeExpr *r = makeNode(ConvertRowtypeExpr);
+
+					r->arg = (Expr *) var;
+					r->resulttype = context->old_rel_type;
+					r->convertformat = COERCE_IMPLICIT_CAST;
+					/* Make sure the Var node has the right type ID, too */
+					Assert(var->vartype == context->old_rel_type);
+					var->vartype = context->new_rel_type;
+					return (Node *) r;
+				}
 			}
 			/* system attributes don't need any translation */
 		}

src/backend/optimizer/util/clauses.c

@@ -8,7 +8,7 @@
  *
  *
  * IDENTIFICATION
- *	  $PostgreSQL: pgsql/src/backend/optimizer/util/clauses.c,v 1.184 2004/11/09 21:42:53 tgl Exp $
+ *	  $PostgreSQL: pgsql/src/backend/optimizer/util/clauses.c,v 1.185 2004/12/11 23:26:39 tgl Exp $
  *
  * HISTORY
  *	  AUTHOR			DATE			MAJOR EVENT
@@ -1047,6 +1047,13 @@ strip_implicit_coercions(Node *node)
 		if (r->relabelformat == COERCE_IMPLICIT_CAST)
 			return strip_implicit_coercions((Node *) r->arg);
 	}
+	else if (IsA(node, ConvertRowtypeExpr))
+	{
+		ConvertRowtypeExpr *c = (ConvertRowtypeExpr *) node;
+
+		if (c->convertformat == COERCE_IMPLICIT_CAST)
+			return strip_implicit_coercions((Node *) c->arg);
+	}
 	else if (IsA(node, CoerceToDomain))
 	{
 		CoerceToDomain *c = (CoerceToDomain *) node;
@@ -1082,11 +1089,13 @@ set_coercionform_dontcare_walker(Node *node, void *context)
 		return false;
 	if (IsA(node, FuncExpr))
 		((FuncExpr *) node)->funcformat = COERCE_DONTCARE;
-	if (IsA(node, RelabelType))
+	else if (IsA(node, RelabelType))
 		((RelabelType *) node)->relabelformat = COERCE_DONTCARE;
-	if (IsA(node, RowExpr))
+	else if (IsA(node, ConvertRowtypeExpr))
+		((ConvertRowtypeExpr *) node)->convertformat = COERCE_DONTCARE;
+	else if (IsA(node, RowExpr))
 		((RowExpr *) node)->row_format = COERCE_DONTCARE;
-	if (IsA(node, CoerceToDomain))
+	else if (IsA(node, CoerceToDomain))
 		((CoerceToDomain *) node)->coercionformat = COERCE_DONTCARE;
 	return expression_tree_walker(node, set_coercionform_dontcare_walker,
 								  context);
@@ -2647,6 +2656,8 @@ expression_tree_walker(Node *node,
 			break;
 		case T_RelabelType:
 			return walker(((RelabelType *) node)->arg, context);
+		case T_ConvertRowtypeExpr:
+			return walker(((ConvertRowtypeExpr *) node)->arg, context);
 		case T_CaseExpr:
 			{
 				CaseExpr   *caseexpr = (CaseExpr *) node;
@@ -3057,6 +3068,16 @@ expression_tree_mutator(Node *node,
 				return (Node *) newnode;
 			}
 			break;
+		case T_ConvertRowtypeExpr:
+			{
+				ConvertRowtypeExpr *convexpr = (ConvertRowtypeExpr *) node;
+				ConvertRowtypeExpr *newnode;
+
+				FLATCOPY(newnode, convexpr, ConvertRowtypeExpr);
+				MUTATE(newnode->arg, convexpr->arg, Expr *);
+				return (Node *) newnode;
+			}
+			break;
 		case T_CaseExpr:
 			{
 				CaseExpr   *caseexpr = (CaseExpr *) node;

src/backend/parser/parse_coerce.c

@@ -8,7 +8,7 @@
  *
  *
  * IDENTIFICATION
- *	  $PostgreSQL: pgsql/src/backend/parser/parse_coerce.c,v 2.124 2004/11/06 17:46:33 tgl Exp $
+ *	  $PostgreSQL: pgsql/src/backend/parser/parse_coerce.c,v 2.125 2004/12/11 23:26:42 tgl Exp $
  *
  *-------------------------------------------------------------------------
  */
@@ -321,13 +321,16 @@ coerce_type(ParseState *pstate, Node *node,
 	if (typeInheritsFrom(inputTypeId, targetTypeId))
 	{
 		/*
-		 * Input class type is a subclass of target, so nothing to do ---
-		 * except relabel the type.  This is binary compatibility for
-		 * complex types.
+		 * Input class type is a subclass of target, so generate an
+		 * appropriate runtime conversion (removing unneeded columns
+		 * and possibly rearranging the ones that are wanted).
 		 */
-		return (Node *) makeRelabelType((Expr *) node,
-										targetTypeId, -1,
-										cformat);
+		ConvertRowtypeExpr *r = makeNode(ConvertRowtypeExpr);
+
+		r->arg = (Expr *) node;
+		r->resulttype = targetTypeId;
+		r->convertformat = cformat;
+		return (Node *) r;
 	}
 	/* If we get here, caller blew it */
 	elog(ERROR, "failed to find conversion function from %s to %s",
@@ -567,6 +570,8 @@ hide_coercion_node(Node *node)
 		((FuncExpr *) node)->funcformat = COERCE_IMPLICIT_CAST;
 	else if (IsA(node, RelabelType))
 		((RelabelType *) node)->relabelformat = COERCE_IMPLICIT_CAST;
+	else if (IsA(node, ConvertRowtypeExpr))
+		((ConvertRowtypeExpr *) node)->convertformat = COERCE_IMPLICIT_CAST;
 	else if (IsA(node, RowExpr))
 		((RowExpr *) node)->row_format = COERCE_IMPLICIT_CAST;
 	else if (IsA(node, CoerceToDomain))

src/backend/parser/parse_expr.c

@@ -8,7 +8,7 @@
  *
  *
  * IDENTIFICATION
- *	  $PostgreSQL: pgsql/src/backend/parser/parse_expr.c,v 1.176 2004/08/29 05:06:44 momjian Exp $
+ *	  $PostgreSQL: pgsql/src/backend/parser/parse_expr.c,v 1.177 2004/12/11 23:26:42 tgl Exp $
  *
  *-------------------------------------------------------------------------
  */
@@ -940,6 +940,7 @@ transformExpr(ParseState *pstate, Node *expr)
 		case T_FieldSelect:
 		case T_FieldStore:
 		case T_RelabelType:
+		case T_ConvertRowtypeExpr:
 		case T_CaseTestExpr:
 		case T_CoerceToDomain:
 		case T_CoerceToDomainValue:
@@ -1406,6 +1407,9 @@ exprType(Node *expr)
 		case T_RelabelType:
 			type = ((RelabelType *) expr)->resulttype;
 			break;
+		case T_ConvertRowtypeExpr:
+			type = ((ConvertRowtypeExpr *) expr)->resulttype;
+			break;
 		case T_CaseExpr:
 			type = ((CaseExpr *) expr)->casetype;
 			break;

src/backend/utils/adt/ruleutils.c

@@ -3,7 +3,7 @@
  *				back to source text
  *
  * IDENTIFICATION
- *	  $PostgreSQL: pgsql/src/backend/utils/adt/ruleutils.c,v 1.185 2004/11/05 19:16:11 tgl Exp $
+ *	  $PostgreSQL: pgsql/src/backend/utils/adt/ruleutils.c,v 1.186 2004/12/11 23:26:45 tgl Exp $
  *
  *	  This software is copyrighted by Jan Wieck - Hamburg.
  *
@@ -2622,6 +2622,9 @@ isSimpleNode(Node *node, Node *parentNode, int prettyFlags)
 		case T_RelabelType:
 			return isSimpleNode((Node *) ((RelabelType *) node)->arg,
 								node, prettyFlags);
+		case T_ConvertRowtypeExpr:
+			return isSimpleNode((Node *) ((ConvertRowtypeExpr *) node)->arg,
+								node, prettyFlags);
 
 		case T_OpExpr:
 			{
@@ -3133,6 +3136,30 @@ get_rule_expr(Node *node, deparse_context *context,
 			}
 			break;
 
+		case T_ConvertRowtypeExpr:
+			{
+				ConvertRowtypeExpr *convert = (ConvertRowtypeExpr *) node;
+				Node	   *arg = (Node *) convert->arg;
+
+				if (convert->convertformat == COERCE_IMPLICIT_CAST &&
+					!showimplicit)
+				{
+					/* don't show the implicit cast */
+					get_rule_expr_paren(arg, context, false, node);
+				}
+				else
+				{
+					if (!PRETTY_PAREN(context))
+						appendStringInfoChar(buf, '(');
+					get_rule_expr_paren(arg, context, false, node);
+					if (!PRETTY_PAREN(context))
+						appendStringInfoChar(buf, ')');
+					appendStringInfo(buf, "::%s",
+							format_type_with_typemod(convert->resulttype, -1));
+				}
+			}
+			break;
+
 		case T_CaseExpr:
 			{
 				CaseExpr   *caseexpr = (CaseExpr *) node;

src/include/nodes/execnodes.h

@@ -7,7 +7,7 @@
  * Portions Copyright (c) 1996-2004, PostgreSQL Global Development Group
  * Portions Copyright (c) 1994, Regents of the University of California
  *
- * $PostgreSQL: pgsql/src/include/nodes/execnodes.h,v 1.120 2004/10/07 18:38:51 tgl Exp $
+ * $PostgreSQL: pgsql/src/include/nodes/execnodes.h,v 1.121 2004/12/11 23:26:49 tgl Exp $
  *
  *-------------------------------------------------------------------------
  */
@@ -578,6 +578,23 @@ typedef struct FieldStoreState
 	TupleDesc	argdesc;		/* tupdesc for most recent input */
 } FieldStoreState;
 
+/* ----------------
+ *		ConvertRowtypeExprState node
+ * ----------------
+ */
+typedef struct ConvertRowtypeExprState
+{
+	ExprState	xprstate;
+	ExprState  *arg;			/* input tuple value */
+	TupleDesc	indesc;			/* tupdesc for source rowtype */
+	TupleDesc	outdesc;		/* tupdesc for result rowtype */
+	AttrNumber *attrMap;		/* indexes of input fields, or 0 for null */
+	Datum	   *invalues;		/* workspace for deconstructing source */
+	char	   *innulls;
+	Datum	   *outvalues;		/* workspace for constructing result */
+	char	   *outnulls;
+} ConvertRowtypeExprState;
+
 /* ----------------
  *		CaseExprState node
  * ----------------

src/include/nodes/nodes.h

@@ -7,7 +7,7 @@
  * Portions Copyright (c) 1996-2004, PostgreSQL Global Development Group
  * Portions Copyright (c) 1994, Regents of the University of California
  *
- * $PostgreSQL: pgsql/src/include/nodes/nodes.h,v 1.161 2004/09/14 03:21:25 tgl Exp $
+ * $PostgreSQL: pgsql/src/include/nodes/nodes.h,v 1.162 2004/12/11 23:26:49 tgl Exp $
  *
  *-------------------------------------------------------------------------
  */
@@ -112,6 +112,7 @@ typedef enum NodeTag
 	T_FieldSelect,
 	T_FieldStore,
 	T_RelabelType,
+	T_ConvertRowtypeExpr,
 	T_CaseExpr,
 	T_CaseWhen,
 	T_CaseTestExpr,
@@ -145,6 +146,7 @@ typedef enum NodeTag
 	T_SubPlanState,
 	T_FieldSelectState,
 	T_FieldStoreState,
+	T_ConvertRowtypeExprState,
 	T_CaseExprState,
 	T_CaseWhenState,
 	T_ArrayExprState,

src/include/nodes/primnodes.h

@@ -10,7 +10,7 @@
  * Portions Copyright (c) 1996-2004, PostgreSQL Global Development Group
  * Portions Copyright (c) 1994, Regents of the University of California
  *
- * $PostgreSQL: pgsql/src/include/nodes/primnodes.h,v 1.104 2004/08/29 05:06:57 momjian Exp $
+ * $PostgreSQL: pgsql/src/include/nodes/primnodes.h,v 1.105 2004/12/11 23:26:49 tgl Exp $
  *
  *-------------------------------------------------------------------------
  */
@@ -591,6 +591,27 @@ typedef struct RelabelType
 	CoercionForm relabelformat; /* how to display this node */
 } RelabelType;
 
+/* ----------------
+ * ConvertRowtypeExpr
+ *
+ * ConvertRowtypeExpr represents a type coercion from one composite type
+ * to another, where the source type is guaranteed to contain all the columns
+ * needed for the destination type plus possibly others; the columns need not
+ * be in the same positions, but are matched up by name.  This is primarily
+ * used to convert a whole-row value of an inheritance child table into a
+ * valid whole-row value of its parent table's rowtype.
+ * ----------------
+ */
+
+typedef struct ConvertRowtypeExpr
+{
+	Expr		xpr;
+	Expr	   *arg;			/* input expression */
+	Oid			resulttype;		/* output type (always a composite type) */
+	/* result typmod is not stored, but must be -1; see RowExpr comments */
+	CoercionForm convertformat; /* how to display this node */
+} ConvertRowtypeExpr;
+
 /*----------
  * CaseExpr - a CASE expression
  *

src/pl/plpgsql/src/pl_exec.c

@@ -3,7 +3,7 @@
  *			  procedural language
  *
  * IDENTIFICATION
- *	  $PostgreSQL: pgsql/src/pl/plpgsql/src/pl_exec.c,v 1.123 2004/11/30 03:50:29 neilc Exp $
+ *	  $PostgreSQL: pgsql/src/pl/plpgsql/src/pl_exec.c,v 1.124 2004/12/11 23:26:51 tgl Exp $
  *
  *	  This software is copyrighted by Jan Wieck - Hamburg.
  *
@@ -4024,6 +4024,9 @@ exec_simple_check_node(Node *node)
 		case T_RelabelType:
 			return exec_simple_check_node((Node *) ((RelabelType *) node)->arg);
 
+		case T_ConvertRowtypeExpr:
+			return exec_simple_check_node((Node *) ((ConvertRowtypeExpr *) node)->arg);
+
 		case T_CaseExpr:
 			{
 				CaseExpr   *expr = (CaseExpr *) node;