Re: Streaming replication on win32, still broken

Heikki Linnakangas <heikki.linnakangas@enterprisedb.com>

From: Heikki Linnakangas <heikki.linnakangas@enterprisedb.com>
To: Magnus Hagander <magnus@hagander.net>
Cc: Fujii Masao <masao.fujii@gmail.com>, PostgreSQL-development <pgsql-hackers@postgresql.org>
Date: 2010-02-18T10:04:56Z
Lists: pgsql-hackers
Magnus Hagander wrote:
> O_DIRECT helps us when we're not going to read the file again, because
> we don't waste cache on it. If we are, which is the case here, it
> should be really bad for performance, since we actually have to do a
> physical read.
> 
> Incidentally, that should also apply to general WAL when archive_mdoe
> is on. Do we optimize for that?

Hmm, no we don't. We do take that into account so that we refrain from
issuing posix_fadvice(DONTNEED) if archive_mode is on, but we don't
disable O_DIRECT. Maybe we should..

-- 
  Heikki Linnakangas
  EnterpriseDB   http://www.enterprisedb.com