Message-ID: <493E8245.2020304@cesmail.net>
Date: Tue, 09 Dec 2008 06:35:49 -0800
From: "M. Edward (Ed) Borasky" <znmeb@cesmail.net>
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To: pgsql-performance@postgresql.org
Subject: Re: file system and raid performance
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Scott Marlowe wrote:
> On Sun, Dec 7, 2008 at 10:59 PM, M. Edward (Ed) Borasky
> <znmeb@cesmail.net> wrote:
>> Ah, but shouldn't a PostgreSQL (or any other database, for that matter=
)
>> have its own set of filesystems tuned to the application's I/O pattern=
s?
>> Sure, there are some people who need to have all of their eggs in one
>> basket because they can't afford multiple baskets. For them, maybe the=

>> OS defaults are the right choice. But if you're building a
>> database-specific server, you can optimize the I/O for that.
>=20
> It's really about a cost / benefits analysis.  20 years ago file
> systems were slow and buggy and a database could, with little work,
> outperform them.  Nowadays, not so much.  I'm guessing that the extra
> cost and effort of maintaining a file system for pgsql outweighs any
> real gain you're likely to see performance wise.
>=20
> But I'm sure that if you implemented one that outran XFS / ZFS / ext3
> et. al. people would want to hear about it.
>=20
I guess I wasn't clear -- I didn't mean a PostgreSQL-specific filesystem
design, although BTRFS does have some things that are "RDBMS-friendly".
I meant that one should hand-tune existing filesystems / hardware for
optimum performance on specific workloads. The tablespaces in PostgreSQL
give you that kind of potential granularity, I think.

--=20
M. Edward (Ed) Borasky, FBG, AB, PTA, PGS, MS, MNLP, NST, ACMC(P), WOM

"A mathematician is a device for turning coffee into theorems." --
Alfr=C3=A9d R=C3=A9nyi via Paul Erd=C5=91s