From: | Bruce Momjian <bruce(at)momjian(dot)us> |
---|---|
To: | Tom Lane <tgl(at)sss(dot)pgh(dot)pa(dot)us> |
Cc: | Dimitri Fontaine <dfontaine(at)hi-media(dot)com>, Josh Berkus <josh(at)agliodbs(dot)com>, postgres performance list <pgsql-performance(at)postgresql(dot)org> |
Subject: | Re: PostgreSQL as a local in-memory cache |
Date: | 2010-06-23 19:40:08 |
Message-ID: | 201006231940.o5NJe8Q05526@momjian.us |
Views: | Raw Message | Whole Thread | Download mbox | Resend email |
Thread: | |
Lists: | pgsql-performance |
Tom Lane wrote:
> Dimitri Fontaine <dfontaine(at)hi-media(dot)com> writes:
> > Josh Berkus <josh(at)agliodbs(dot)com> writes:
> >> a) Eliminate WAL logging entirely
> >> b) Eliminate checkpointing
> >> c) Turn off the background writer
> >> d) Have PostgreSQL refuse to restart after a crash and instead call an
> >> exteral script (for reprovisioning)
>
> > Well I guess I'd prefer a per-transaction setting, allowing to bypass
> > WAL logging and checkpointing.
>
> Not going to happen; this is all or nothing.
>
> > Forcing the backend to care itself for
> > writing the data I'm not sure is a good thing, but if you say so.
>
> Yeah, I think proposal (c) is likely to be a net loss.
>
> (a) and (d) are probably simple, if by "reprovisioning" you mean
> "rm -rf $PGDATA; initdb". Point (b) will be a bit trickier because
> there are various housekeeping activities tied into checkpoints.
> I think you can't actually remove checkpoints altogether, just
> skip the flush-dirty-pages part.
Based on this thread, I have developed the following documentation patch
that outlines the performance enhancements possible if durability is not
required. The patch also documents that synchronous_commit = false has
potential committed transaction loss from a database crash (as well as
an OS crash).
--
Bruce Momjian <bruce(at)momjian(dot)us> http://momjian.us
EnterpriseDB http://enterprisedb.com
+ None of us is going to be here forever. +
Attachment | Content-Type | Size |
---|---|---|
/pgpatches/durability | text/x-diff | 4.0 KB |
From | Date | Subject | |
---|---|---|---|
Next Message | Pavel Stehule | 2010-06-23 19:51:26 | Re: PostgreSQL as a local in-memory cache |
Previous Message | Bruce Momjian | 2010-06-23 19:37:20 | Re: PostgreSQL as a local in-memory cache |