Re: Running PostgreSQL as fast as possible no matter the consequences

Jeff Janes wrote:
> On Tue, Jan 25, 2011 at 5:32 PM, Bruce Momjian <bruce(at)momjian(dot)us> wrote:
> > Robert Haas wrote:
> >> On Wed, Jan 19, 2011 at 12:07 PM, Bruce Momjian <bruce(at)momjian(dot)us> wrote:
>
> >> > ? ? ? ?http://developer.postgresql.org/pgdocs/postgres/non-durability.html
> >>
> >> This sentence looks to me like it should be removed, or perhaps clarified:
> >>
> >> ? ? This does affect database crash transaction durability.
> >
> > Uh, doesn't it affect database crash transaction durability? ?I have
> > applied the attached patch to clarify things. ?Thanks.
>
> I think the point that was trying to be made there was that the other
> parameters only lose and corrupt data when the machine crashes.
> Synchronous commit turned off will lose data on a mere postgresql
> server crash, it doesn't require a machine-level crash to cause data
> loss.
>
> Indeed, the currently committed doc is quite misleading.
>
> " The following are configuration changes you can make
> to improve performance in such cases; they do not invalidate
> commit guarantees related to database crashes, only abrupt operating
> system stoppage, except as mentioned below"
>
> We've now removed the thing being mentioned below, but did not remove
> the promise we would be mentioning those things.

Excellent point. The old wording was just too clever and even I forgot
why I was making that point. I have updated the docs to clearly state
why this setting is different from the ones above. Thanks for spotting
this.

Applied patch attached.

--
Bruce Momjian <bruce(at)momjian(dot)us> http://momjian.us
EnterpriseDB http://enterprisedb.com

+ It's impossible for everything to be true. +