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/include/access/genam.h

@@ -6,7 +6,7 @@
  *
  * Copyright (c) 1994, Regents of the University of California
  *
- * $Id: genam.h,v 1.4 1996/11/05 08:18:09 scrappy Exp $
+ * $Id: genam.h,v 1.5 1996/11/13 20:50:28 scrappy Exp $
  *
  *-------------------------------------------------------------------------
  */
@@ -27,7 +27,8 @@ extern Relation index_openr(char *relationName);
 extern void index_close(Relation relation);
 extern InsertIndexResult index_insert(Relation relation,
 				      Datum *datum, char *nulls,
-				      ItemPointer heap_t_ctid);
+				      ItemPointer heap_t_ctid,
+				      bool is_update);
 extern void index_delete(Relation relation, ItemPointer indexItem);
 extern IndexScanDesc index_beginscan(Relation relation, bool scanFromEnd,
      uint16 numberOfKeys, ScanKey key);

src/include/access/gist.h

@@ -174,7 +174,7 @@ extern void gistbuild(Relation heap,
 	  FuncIndexInfo *finfo,
 	  PredInfo *predInfo);
 extern InsertIndexResult gistinsert(Relation r, Datum *datum,
-			char *nulls,ItemPointer ht_ctid);
+			char *nulls,ItemPointer ht_ctid, bool is_update);
 extern void _gistdump(Relation r);
 extern char *text_range_out(TXTRANGE *r);
 extern char *int_range_out(INTRANGE *r);

src/include/access/hash.h

@@ -6,7 +6,7 @@
  *
  * Copyright (c) 1994, Regents of the University of California
  *
- * $Id: hash.h,v 1.4 1996/11/10 03:04:36 momjian Exp $
+ * $Id: hash.h,v 1.5 1996/11/13 20:50:31 scrappy Exp $
  *
  * NOTES
  *	modeled after Margo Seltzer's hash implementation for unix. 
@@ -255,7 +255,7 @@ extern void hashbuild(Relation heap, Relation index, int natts,
 	AttrNumber *attnum, IndexStrategy istrat, uint16 pcount,
 	Datum *params, FuncIndexInfo *finfo, PredInfo *predInfo);
 extern InsertIndexResult hashinsert(Relation rel, Datum *datum, char *nulls,
-				    ItemPointer ht_ctid);
+				    ItemPointer ht_ctid, bool is_update);
 extern char *hashgettuple(IndexScanDesc scan, ScanDirection dir);
 extern char *hashbeginscan(Relation rel, bool fromEnd, uint16 keysz,
 			   ScanKey scankey);

src/include/access/nbtree.h

@@ -6,7 +6,7 @@
  *
  * Copyright (c) 1994, Regents of the University of California
  *
- * $Id: nbtree.h,v 1.3 1996/11/05 10:37:08 scrappy Exp $
+ * $Id: nbtree.h,v 1.4 1996/11/13 20:50:32 scrappy Exp $
  *
  *-------------------------------------------------------------------------
  */
@@ -170,7 +170,10 @@ typedef BTStackData	*BTStack;
 /*
  * prototypes for functions in nbtinsert.c
  */
-extern InsertIndexResult _bt_doinsert(Relation rel, BTItem btitem);
+extern InsertIndexResult _bt_doinsert(Relation rel, BTItem btitem,
+				      bool index_is_unique, bool is_update);
+
+				/* default is to allow duplicates */
 extern bool _bt_itemcmp(Relation rel, Size keysz, BTItem item1, BTItem item2,
 			StrategyNumber strat);
 
@@ -200,7 +203,7 @@ extern void btbuild(Relation heap, Relation index, int natts,
 	AttrNumber *attnum, IndexStrategy istrat, uint16 pcount,
 	Datum *params, FuncIndexInfo *finfo, PredInfo *predInfo);
 extern InsertIndexResult btinsert(Relation rel, Datum *datum, char *nulls,
-				  ItemPointer ht_ctid);
+				  ItemPointer ht_ctid, bool is_update);
 extern char *btgettuple(IndexScanDesc scan, ScanDirection dir);
 extern char *btbeginscan(Relation rel, bool fromEnd, uint16 keysz,
 			 ScanKey scankey);
@@ -237,6 +240,7 @@ extern OffsetNumber _bt_binsrch(Relation rel, Buffer buf, int keysz,
 extern RetrieveIndexResult _bt_next(IndexScanDesc scan, ScanDirection dir);
 extern RetrieveIndexResult _bt_first(IndexScanDesc scan, ScanDirection dir);
 extern bool _bt_step(IndexScanDesc scan, Buffer *bufP, ScanDirection dir);
+extern int _bt_compare(Relation rel, TupleDesc itupdesc, Page page, int keysz, ScanKey scankey, OffsetNumber offnum);
 
 /*
  * prototypes for functions in nbtstrat.c

src/include/access/rtree.h

@@ -6,7 +6,7 @@
  *
  * Copyright (c) 1994, Regents of the University of California
  *
- * $Id: rtree.h,v 1.3 1996/11/10 03:04:39 momjian Exp $
+ * $Id: rtree.h,v 1.4 1996/11/13 20:50:34 scrappy Exp $
  *
  *-------------------------------------------------------------------------
  */
@@ -112,7 +112,7 @@ extern RetrieveIndexResult rtgettuple(IndexScanDesc s, ScanDirection dir);
  *	Defined in access/index-rtree/
  */
 extern InsertIndexResult rtinsert(Relation r, Datum *datum, char *nulls,
-			ItemPointer ht_ctid);
+			ItemPointer ht_ctid, bool is_update);
 extern char *rtdelete(Relation r, ItemPointer tid);
 
 extern RetrieveIndexResult rtgettuple(IndexScanDesc s, ScanDirection dir);