Re: pgsql-server: Add: > > * Allow buffered WAL writes - Mailing list pgsql-committers

From Bruce Momjian
Subject Re: pgsql-server: Add: > > * Allow buffered WAL writes
Date
Msg-id 200408140411.i7E4BEE01687@candle.pha.pa.us
Whole thread Raw
In response to Re: pgsql-server: Add: > > * Allow buffered WAL writes  ("Marc G. Fournier" <scrappy@postgresql.org>)
Responses Re: pgsql-server: Add: > > * Allow buffered WAL writes
List pgsql-committers
Marc G. Fournier wrote:
> On Sat, 14 Aug 2004, Tom Lane wrote:
>
> > Bruce Momjian <pgman@candle.pha.pa.us> writes:
> >> Many databases offer this feature.  The submitter asked for it,
> >
> > Actually he didn't --- AFAICS you misinterpreted the thread completely.
> > The original suggestion was that we might be able to exploit a
> > transactional filesystem to improve performance *without* sacrificing
> > any correctness guarantees.  Delayed fsync has nothing to do with that.
> >
> > (I'm dubious whether there's any performance improvement to be had that
> > would be worth the code uglification involved, since we're surely not
> > going to *require* a transactional filesystem and so two very different
> > code paths seem to be needed.  But it's at least something to think about.)
>
> Just to expand on the 'dubiousness' ... remember awhile back when I worked
> through the 'no-WAL' version of PostgreSQL to test loading a database with
> WAL disabled?  The performance improvements on loading a database weren't
> enough, I seem to recall, to warrant getting rid of WAL altogether ... so
> I can't see 'delayed WAL' being faster then 'no WAL' ...

Uh, you mean fsync isn't a performance hit as it once was?

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