Major planner/optimizer revision: get rid of PathOrder node type,

store all ordering information in pathkeys lists (which are now lists of
lists of PathKeyItem nodes, not just lists of lists of vars).  This was
a big win --- the code is smaller and IMHO more understandable than it
was, even though it handles more cases.  I believe the node changes will
not force an initdb for anyone; planner nodes don't show up in stored
rules.

src/include/nodes/primnodes.h

@@ -6,7 +6,7 @@
  *
  * Copyright (c) 1994, Regents of the University of California
  *
- * $Id: primnodes.h,v 1.32 1999/07/18 03:45:01 tgl Exp $
+ * $Id: primnodes.h,v 1.33 1999/08/16 02:17:39 tgl Exp $
  *
  *-------------------------------------------------------------------------
  */
@@ -255,6 +255,20 @@ typedef struct Func
 	List	   *func_planlist;
 } Func;
 
+/* ----------------
+ * Iter
+ *		can anyone explain what this is for?  Seems to have something to do
+ *		with evaluation of functions that return sets...
+ * ----------------
+ */
+typedef struct Iter
+{
+	NodeTag		type;
+	Node	   *iterexpr;
+	Oid			itertype;		/* type of the iter expr (use for type
+								 * checking) */
+} Iter;
+
 /* ----------------
  * Aggref
  *		aggname			- name of the aggregate