| From: | "ktm(at)rice(dot)edu" <ktm(at)rice(dot)edu> |
|---|---|
| To: | Jon Nelson <jnelson+pgsql(at)jamponi(dot)net> |
| Cc: | Jim Nasby <jim(at)nasby(dot)net>, Jeff Janes <jeff(dot)janes(at)gmail(dot)com>, Greg Stark <stark(at)mit(dot)edu>, Amit Kapila <amit(dot)kapila(at)huawei(dot)com>, Simon Riggs <simon(at)2ndquadrant(dot)com>, Tom Lane <tgl(at)sss(dot)pgh(dot)pa(dot)us>, Jeff Davis <pgsql(at)j-davis(dot)com>, Florian Pflug <fgp(at)phlo(dot)org>, Andres Freund <andres(at)2ndquadrant(dot)com>, Fujii Masao <masao(dot)fujii(at)gmail(dot)com>, PostgreSQL-development <pgsql-hackers(at)postgresql(dot)org> |
| Subject: | Re: corrupt pages detected by enabling checksums |
| Date: | 2013-05-13 12:49:09 |
| Message-ID: | 20130513124909.GA27807@aart.rice.edu |
| Views: | Raw Message | Whole Thread | Download mbox | Resend email |
| Thread: | |
| Lists: | pgsql-hackers |
On Sun, May 12, 2013 at 07:41:26PM -0500, Jon Nelson wrote:
> On Sun, May 12, 2013 at 3:46 PM, Jim Nasby <jim(at)nasby(dot)net> wrote:
> > On 5/10/13 1:06 PM, Jeff Janes wrote:
> >>
> >> Of course the paranoid DBA could turn off restart_after_crash and do a
> >> manual investigation on every crash, but in that case the database would
> >> refuse to restart even in the case where it perfectly clear that all the
> >> following WAL belongs to the recycled file and not the current file.
> >
> >
> > Perhaps we should also allow for zeroing out WAL files before reuse (or just
> > disable reuse). I know there's a performance hit there, but the reuse idea
> > happened before we had bgWriter. Theoretically the overhead creating a new
> > file would always fall to bgWriter and therefore not be a big deal.
>
> For filesystems like btrfs, re-using a WAL file is suboptimal to
> simply creating a new one and removing the old one when it's no longer
> required. Using fallocate (or posix_fallocate) (I have a patch for
> that!) to create a new one is - by my tests - 28 times faster than the
> currently-used method.
>
>
> --
> Jon
>
What about for less cutting (bleeding) edge filesystems?
Ken
| From | Date | Subject | |
|---|---|---|---|
| Next Message | Heikki Linnakangas | 2013-05-13 12:50:03 | Better LWLocks with compare-and-swap (9.4) |
| Previous Message | ktm@rice.edu | 2013-05-13 12:46:55 | Re: corrupt pages detected by enabling checksums |