Re: PostgreSQL as a local in-memory cache

Robert Haas wrote:
> On Tue, Jun 29, 2010 at 9:32 AM, Bruce Momjian <bruce@momjian.us> wrote:
> > Robert Haas wrote:
> >> On Mon, Jun 28, 2010 at 5:57 PM, Bruce Momjian <bruce@momjian.us> wrote:
> >> >> The patch also documents that synchronous_commit = false has
> >> >> potential committed transaction loss from a database crash (as well as
> >> >> an OS crash).
> >>
> >> Is this actually true?
> >
> > I asked on IRC and was told it is true, and looking at the C code it
> > looks true. ?What synchronous_commit = false does is to delay writing
> > the wal buffers to disk and fsyncing them, not just fsync, which is
> > where the commit loss due to db process crash comes from.
>
> Ah, I see.  Thanks.

I am personally surprised it was designed that way;  I thought we would
just delay fsync.

--
  Bruce Momjian  <bruce@momjian.us>        http://momjian.us
  EnterpriseDB                             http://enterprisedb.com

  + None of us is going to be here forever. +