*
*
* IDENTIFICATION
- * $PostgreSQL: pgsql/src/backend/access/nbtree/nbtpage.c,v 1.112 2009/01/01 17:23:35 momjian Exp $
+ * $PostgreSQL: pgsql/src/backend/access/nbtree/nbtpage.c,v 1.113 2009/05/05 19:02:22 tgl Exp $
*
* NOTES
* Postgres btree pages look like ordinary relation pages. The opaque
* This is equivalent to _bt_relbuf followed by _bt_getbuf, with the
* exception that blkno may not be P_NEW. Also, if obuf is InvalidBuffer
* then it reduces to just _bt_getbuf; allowing this case simplifies some
- * callers. The motivation for using this is to avoid two entries to the
- * bufmgr when one will do.
+ * callers.
+ *
+ * The original motivation for using this was to avoid two entries to the
+ * bufmgr when one would do. However, now it's mainly just a notational
+ * convenience. The only case where it saves work over _bt_relbuf/_bt_getbuf
+ * is when the target page is the same one already in the buffer.
*/
Buffer
_bt_relandgetbuf(Relation rel, Buffer obuf, BlockNumber blkno, int access)