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, 8 insertions, 47 deletions

diff --git a/src/backend/parser/parse_func.c b/src/backend/parser/parse_func.c
index 766a5daad55..ed39d6c1036 100644
--- a/src/backend/parser/parse_func.c
+++ b/src/backend/parser/parse_func.c
@@ -8,7 +8,7 @@
  *
  *
  * IDENTIFICATION
- *	  $Header: /cvsroot/pgsql/src/backend/parser/parse_func.c,v 1.116 2002/02/19 20:11:15 tgl Exp $
+ *	  $Header: /cvsroot/pgsql/src/backend/parser/parse_func.c,v 1.117 2002/03/12 00:51:55 tgl Exp $
  *
  *-------------------------------------------------------------------------
  */
@@ -316,7 +316,6 @@ ParseFuncOrColumn(ParseState *pstate, char *funcname, List *fargs,
 		{
 			RangeTblEntry *rte;
 			int			vnum;
-			Node	   *rteorjoin;
 			int			sublevels_up;
 
 			/*
@@ -324,49 +323,11 @@ ParseFuncOrColumn(ParseState *pstate, char *funcname, List *fargs,
 			 */
 			refname = ((Ident *) arg)->name;
 
-			rteorjoin = refnameRangeOrJoinEntry(pstate, refname,
-												&sublevels_up);
+			rte = refnameRangeTblEntry(pstate, refname,
+									   &sublevels_up);
 
-			if (rteorjoin == NULL)
+			if (rte == NULL)
 				rte = addImplicitRTE(pstate, refname);
-			else if (IsA(rteorjoin, RangeTblEntry))
-				rte = (RangeTblEntry *) rteorjoin;
-			else if (IsA(rteorjoin, JoinExpr))
-			{
-				/*
-				 * The relation name refers to a join.	We can't support
-				 * functions on join tuples (since we don't have a named
-				 * type for the join tuples), so error out.
-				 */
-				if (nargs == 1)
-				{
-					/*
-					 * We have f(x) or more likely x.f where x is a join
-					 * and f is not one of the attribute names of the join
-					 * (else we'd have recognized it above).  Give an
-					 * appropriately vague error message.  Would be nicer
-					 * to know which syntax was used...
-					 */
-					elog(ERROR, "No such attribute or function %s.%s",
-						 refname, funcname);
-				}
-				else
-				{
-					/*
-					 * There are multiple arguments, so it must be a
-					 * function call.
-					 */
-					elog(ERROR, "Cannot pass result of join %s to a function",
-						 refname);
-				}
-				rte = NULL;		/* keep compiler quiet */
-			}
-			else
-			{
-				elog(ERROR, "ParseFuncOrColumn: unexpected node type %d",
-					 nodeTag(rteorjoin));
-				rte = NULL;		/* keep compiler quiet */
-			}
 
 			vnum = RTERangeTablePosn(pstate, rte, &sublevels_up);
 
@@ -379,11 +340,11 @@ ParseFuncOrColumn(ParseState *pstate, char *funcname, List *fargs,
 			 * sizeof(Pointer) to signal that the runtime representation
 			 * will be a pointer not an Oid.
 			 */
-			if (rte->relname == NULL)
+			if (rte->rtekind != RTE_RELATION)
 			{
 				/*
-				 * RTE is a subselect; must fail for lack of a specific
-				 * type
+				 * RTE is a join or subselect; must fail for lack of a
+				 * named tuple type
 				 */
 				if (nargs == 1)
 				{
@@ -397,7 +358,7 @@ ParseFuncOrColumn(ParseState *pstate, char *funcname, List *fargs,
 				}
 				else
 				{
-					elog(ERROR, "Cannot pass result of sub-select %s to a function",
+					elog(ERROR, "Cannot pass result of sub-select or join %s to a function",
 						 refname);
 				}
 			}