Restructure representation of join alias variables. An explicit JOIN

now has an RTE of its own, and references to its outputs now are Vars
referencing the JOIN RTE, rather than CASE-expressions.  This allows
reverse-listing in ruleutils.c to use the correct alias easily, rather
than painfully reverse-engineering the alias namespace as it used to do.
Also, nested FULL JOINs work correctly, because the result of the inner
joins are simple Vars that the planner can cope with.  This fixes a bug
reported a couple times now, notably by Tatsuo on 18-Nov-01.  The alias
Vars are expanded into COALESCE expressions where needed at the very end
of planning, rather than during parsing.
Also, beginnings of support for showing plan qualifier expressions in
EXPLAIN.  There are probably still cases that need work.
initdb forced due to change of stored-rule representation.

1 files changed, 7 insertions, 46 deletions

diff --git a/src/backend/parser/parse_node.c b/src/backend/parser/parse_node.c
index a43dcb13af2..be825c26f9e 100644
--- a/src/backend/parser/parse_node.c
+++ b/src/backend/parser/parse_node.c
@@ -8,21 +8,22 @@
  *
  *
  * IDENTIFICATION
- *	  $Header: /cvsroot/pgsql/src/backend/parser/parse_node.c,v 1.58 2002/03/06 06:09:54 momjian Exp $
+ *	  $Header: /cvsroot/pgsql/src/backend/parser/parse_node.c,v 1.59 2002/03/12 00:51:55 tgl Exp $
  *
  *-------------------------------------------------------------------------
  */
+#include "postgres.h"
+
 #include <ctype.h>
 #include <errno.h>
 #include <float.h>
 
-#include "postgres.h"
-
 #include "access/heapam.h"
 #include "catalog/pg_operator.h"
 #include "catalog/pg_type.h"
 #include "fmgr.h"
 #include "nodes/makefuncs.h"
+#include "parser/parsetree.h"
 #include "parser/parse_coerce.h"
 #include "parser/parse_expr.h"
 #include "parser/parse_node.h"
@@ -165,51 +166,11 @@ make_var(ParseState *pstate, RangeTblEntry *rte, int attrno)
 {
 	int			vnum,
 				sublevels_up;
-	Oid			vartypeid = 0;
-	int32		type_mod = 0;
+	Oid			vartypeid;
+	int32		type_mod;
 
 	vnum = RTERangeTablePosn(pstate, rte, &sublevels_up);
-
-	if (rte->relid != InvalidOid)
-	{
-		/* Plain relation RTE --- get the attribute's type info */
-		HeapTuple	tp;
-		Form_pg_attribute att_tup;
-
-		tp = SearchSysCache(ATTNUM,
-							ObjectIdGetDatum(rte->relid),
-							Int16GetDatum(attrno),
-							0, 0);
-		/* this shouldn't happen... */
-		if (!HeapTupleIsValid(tp))
-			elog(ERROR, "Relation %s does not have attribute %d",
-				 rte->relname, attrno);
-		att_tup = (Form_pg_attribute) GETSTRUCT(tp);
-		vartypeid = att_tup->atttypid;
-		type_mod = att_tup->atttypmod;
-		ReleaseSysCache(tp);
-	}
-	else
-	{
-		/* Subselect RTE --- get type info from subselect's tlist */
-		List	   *tlistitem;
-
-		foreach(tlistitem, rte->subquery->targetList)
-		{
-			TargetEntry *te = (TargetEntry *) lfirst(tlistitem);
-
-			if (te->resdom->resjunk || te->resdom->resno != attrno)
-				continue;
-			vartypeid = te->resdom->restype;
-			type_mod = te->resdom->restypmod;
-			break;
-		}
-		/* falling off end of list shouldn't happen... */
-		if (tlistitem == NIL)
-			elog(ERROR, "Subquery %s does not have attribute %d",
-				 rte->eref->relname, attrno);
-	}
-
+	get_rte_attribute_type(rte, attrno, &vartypeid, &type_mod);
 	return makeVar(vnum, attrno, vartypeid, type_mod, sublevels_up);
 }