From: | Larry Rosenman <ler(at)lerctr(dot)org> |
---|---|
To: | Bruce Momjian <pgman(at)candle(dot)pha(dot)pa(dot)us> |
Cc: | Tom Lane <tgl(at)sss(dot)pgh(dot)pa(dot)us>, Peter Eisentraut <peter_e(at)gmx(dot)net>, pgsql-hackers(at)postgresql(dot)org |
Subject: | Re: Allowing WAL fsync to be done via O_SYNC |
Date: | 2001-03-15 21:12:36 |
Message-ID: | 20010315.21123600@ler-freebie.iadfw.net |
Views: | Raw Message | Whole Thread | Download mbox | Resend email |
Thread: | |
Lists: | pgsql-hackers |
I'd actually vote for it to remain for a release or two or more, as
we get more experience with stuff, the defaults may be different for
different workloads.
LER
--
Larry Rosenman
http://www.lerctr.org/~ler/
Phone: +1 972 414 9812
E-Mail: ler(at)lerctr(dot)org
US Mail: 1905 Steamboat Springs Drive, Garland, TX 75044-6749 US
>>>>>>>>>>>>>>>>>> Original Message <<<<<<<<<<<<<<<<<<
On 3/15/01, 2:46:20 PM, Bruce Momjian <pgman(at)candle(dot)pha(dot)pa(dot)us> wrote
regarding Re: [HACKERS] Allowing WAL fsync to be done via O_SYNC:
> > Bruce Momjian <pgman(at)candle(dot)pha(dot)pa(dot)us> writes:
> > > I later read Vadim's comment that fsync() of two blocks may be faster
> > > than two O_* writes, so I am now confused about the proper solution.
> > > However, I think we need to pick one and make it invisible to the user.
> > > Perhaps a compiler/config.h flag for testing would be a good solution.
> >
> > I believe that we don't know enough yet to nail down a hard-wired
> > decision. Vadim's idea of preferring O_DSYNC if it appears to be
> > different from O_SYNC is a good first cut, but I think we'd better make
> > it possible to override that, at least for testing purposes.
> >
> > So I think it should be configurable at *some* level. I don't much care
> > whether it's a config.h entry or a GUC variable.
> >
> > But consider this: we'll be more likely to get some feedback from the
> > field (allowing us to refine the policy in future releases) if it is a
> > GUC variable. Not many people will build two versions of the software,
> > but people might take the trouble to play with a run-time configuration
> > setting.
> Yes, I can imagine. Can we remove it once we know the answer?
> --
> Bruce Momjian | http://candle.pha.pa.us
> pgman(at)candle(dot)pha(dot)pa(dot)us | (610) 853-3000
> + If your life is a hard drive, | 830 Blythe Avenue
> + Christ can be your backup. | Drexel Hill, Pennsylvania 19026
> ---------------------------(end of broadcast)---------------------------
> TIP 5: Have you checked our extensive FAQ?
From | Date | Subject | |
---|---|---|---|
Next Message | Roberto Mello | 2001-03-15 21:13:49 | Contribute to the PL/pgSQL CookBook !! |
Previous Message | Bruce Momjian | 2001-03-15 20:46:20 | Re: Allowing WAL fsync to be done via O_SYNC |