Обсуждение: pgsql: Dept.

Log Message:
-----------
Dept. of second thoughts: add comments cautioning against using
ReadOrZeroBuffer to fetch pages from beyond physical EOF.  This would
usually work, but would cause problems for md.c if writes occurred
beyond a segment boundary when the previous segment file hadn't been
fully extended.

Modified Files:
--------------
    pgsql/src/backend/storage/buffer:
        bufmgr.c (r1.217 -> r1.218)
        (http://developer.postgresql.org/cvsweb.cgi/pgsql/src/backend/storage/buffer/bufmgr.c.diff?r1=1.217&r2=1.218)