Andrew - Supernews wrote:
> On 2005-08-12, Alvaro Herrera <alvherre@alvh.no-ip.org> wrote:
> > In light of this, may I ask whether it makes sense to compare the
> > performance of two runs with similar shared_buffer settings? With
> > O_DIRECT, I understand from this manpage that the OS is going to do
> > little or no page caching, so shared_buffers should be increased to
> > account for this fact.
> >
> > Am I missing something?
>
> O_DIRECT should only be being used for the WAL, not for buffer I/O.
And only when open_sync or open_datasync are used. But the group write
patch is used in all cases, but again only WAL.
-- Bruce Momjian | http://candle.pha.pa.us pgman@candle.pha.pa.us | (610)
359-1001+ If your life is a hard drive, | 13 Roberts Road + Christ can be your backup. | Newtown Square,
Pennsylvania19073