Horton

RE: RE: [COMMITTERS] pgsql/src/backend/access/transam ( xact.c xlog.c)

Vadim Mikheev <vmikheev@sectorbase.com>

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From: "Mikheev, Vadim" <vmikheev@SECTORBASE.COM>
To: "'Tom Lane'" <tgl@sss.pgh.pa.us>, Bruce Momjian <pgman@candle.pha.pa.us>
Cc: Alfred Perlstein <bright@wintelcom.net>, Tatsuo Ishii <t-ishii@sra.co.jp>, peter_e@gmx.net, pgsql-hackers@postgresql.org
Date: 2000-11-15T18:50:56Z
Lists: pgsql-hackers 
> Earlier, Vadim was talking about arranging to share fsyncs of the WAL
> log file across transactions (after writing your commit record to the
> log, sleep a few milliseconds to see if anyone else fsyncs before you
> do; if not, issue the fsync yourself).  That would offer less-than-
> one-fsync-per-transaction performance without giving up any 
> guarantees.
> If people feel a compulsion to have a tunable parameter, let 'em tune
> the length of the pre-fsync sleep ...

Already implemented (without ability to tune this parameter - 
xact.c:CommitDelay, - yet). Currently CommitDelay is 5, so
backend sleeps 1/200 sec before checking/forcing log fsync.

Vadim