Further work on connecting the free space map (which is still just a

stub) into the rest of the system.  Adopt a cleaner approach to preventing
deadlock in concurrent heap_updates: allow RelationGetBufferForTuple to
select any page of the rel, and put the onus on it to lock both buffers
in a consistent order.  Remove no-longer-needed isExtend hack from
API of ReleaseAndReadBuffer.

src/include/access/hio.h

@@ -7,7 +7,7 @@
  * Portions Copyright (c) 1996-2001, PostgreSQL Global Development Group
  * Portions Copyright (c) 1994, Regents of the University of California
  *
- * $Id: hio.h,v 1.18 2001/05/16 22:35:12 tgl Exp $
+ * $Id: hio.h,v 1.19 2001/06/29 21:08:25 tgl Exp $
  *
  *-------------------------------------------------------------------------
  */
@@ -19,6 +19,6 @@
 extern void RelationPutHeapTuple(Relation relation, Buffer buffer,
 					 HeapTuple tuple);
 extern Buffer RelationGetBufferForTuple(Relation relation, Size len,
-										BlockNumber minblocknum);
+										Buffer otherBuffer);
 
 #endif	 /* HIO_H */