Commit of a *MAJOR* patch from Dan McGuirk <djm@indirect.com>

Changes:

        * Unique index capability works using the syntax 'create unique
          index'.

        * Duplicate OID's in the system tables are removed.  I put
          little scripts called 'duplicate_oids' and 'find_oid' in
          include/catalog that help to find and remove duplicate OID's.
          I also moved 'unused_oids' from backend/catalog to
          include/catalog, since it has to be in the same directory
          as the include files in order to work.

        * The backend tries converting the name of a function or aggregate
          to all lowercase if the original name given doesn't work (mostly
          for compatibility with ODBC).

        * You can 'SELECT NULL' to your heart's content.

        * I put my _bt_updateitem fix in instead, which uses
          _bt_insertonpg so that even if the new key is so big that
          the page has to be split, everything still works.

        * All literal references to system catalog OID's have been
          replaced with references to define'd constants from the catalog
          header files.

        * I added a couple of node copy functions.  I think this was a
          preliminary attempt to get rules to work.

src/backend/executor/execUtils.c

@@ -7,7 +7,7 @@
  *
  *
  * IDENTIFICATION
- *    $Header: /cvsroot/pgsql/src/backend/executor/execUtils.c,v 1.5 1996/11/10 02:59:49 momjian Exp $
+ *    $Header: /cvsroot/pgsql/src/backend/executor/execUtils.c,v 1.6 1996/11/13 20:48:34 scrappy Exp $
  *
  *-------------------------------------------------------------------------
  */
@@ -1025,7 +1025,8 @@ ExecFormIndexTuple(HeapTuple heapTuple,
 void
 ExecInsertIndexTuples(TupleTableSlot *slot,
 		      ItemPointer tupleid,
-		      EState *estate)
+		      EState *estate,
+		      bool is_update)
 {
     HeapTuple			heapTuple;
     RelationInfo	        *resultRelationInfo;
@@ -1104,7 +1105,8 @@ ExecInsertIndexTuples(TupleTableSlot *slot,
 	result = index_insert(relationDescs[i], /* index relation */
 			      datum,  /* array of heaptuple Datums */
 			      nulls, /* info on nulls */
- 			      &(heapTuple->t_ctid)); /* oid of heap tuple */
+ 			      &(heapTuple->t_ctid),
+			      is_update); /* oid of heap tuple */
 	
 	/* ----------------
 	 *	keep track of index inserts for debugging
@@ -1120,4 +1122,3 @@ ExecInsertIndexTuples(TupleTableSlot *slot,
     }
     if (econtext != NULL) pfree(econtext);
 }
-