Re: RAID0 and pg_xlog

> On Fri, 2005-09-09 at 18:54, Jim C. Nasby wrote:
> > On Fri, Sep 09, 2005 at 06:20:21PM -0500, Scott Marlowe wrote:
> > > > pgpool is a connection pool; it has (almost) nothing to do with
> > > > replication. It certainly doesn't work to provide any kind of data
> > > > security on a RAID0 setup.
> > > >
> > > > I'm not arguing against anything people have suggested, only pointing
> > > > out that if you're using RAID0 your data is not safe against a drive
> > > > failure, except possible using pgcluster (some would argue that
> > > > statement-based replication isn't as reliable as log-based).
> > >
> > > Um. No. It has a synchronous replication mode, which I've used, and it
> > > works quite well.
> > >
> > > Look it up, it's pretty cool. Writes to both pg machines synchronously,
> > > reads from them load balanced. Of course, there are some limits imposed
> > > by this methodology, re: things like random() and such.
> > >
> > > Now, if you're arguing against statement based replication, that I can
> > > understand. but pgpool can definitely do two box sync replication.
> >
> > Oh, I didn't realize that. Though I have to wonder why they duplicated
> > what pgcluster provides...
>
> I doubt it's as good as pgcluster. It's simple dual machine sync
> replication. I think it was a case of being 95% there when the pooling
> part was done, so why not just toss in replication for good measure.

As a developer of pgpool I have to admit above. If it's technically
possible, why not chalenge it? That's a nature of an engineer:-)

BTW, some codes(probably the connection pooling part) in PGCluster
have been copied from pgpool. Instead I have been getting good
feedbacks/bug fixes from the author of PGCluster. It is kind of a
collaboration work, and I think this is one of the greatest thing with
open source softwares.
--
SRA OSS, Inc. Japan
Tatsuo Ishii