Re: PostgreSQL on Linux and Solaris comparison

On 31 Oct 2002, Chris wrote:

> Hi,
>
> I am using PostgresSQL 7.1.3 on both Linux and Solaris envrionment.
> Development is using the Linux and production is using Solaris. I
> experienced that the perfomrance on Solaris is much worse than Linux.
> For example, the same query executed 9 seconds on Solaris and only 1
> seconds on Linux.
>
> Is there any help upgrading the 7.1.3 to 7.2.3? Or how can I do some
> performance tunning on Solaris?

There are several issues at play here, some of which you can fix, some of
which you can't.

One is that older flavors of Solaris had a broken sort() command built
into them that was VERY slow when sorting a list with lots of non-unique
keys.

Another is that fact that Solaris has a "heavy process, light thread"
scheduler design.  This means that Solaris favors a few processes with
many threads for good performance, while Postgresql is programmed on the
many processes, what the heck is a thread design.

The many process no thread design is very robust.  But not so fast on
Solaris and Windows, where threads are the preferred implementation
method.

On Linux, threads and processes are equally fast, so the design of
Postgresql is no problem there.

If you have time to play, you might try loading debian on your Sparc boxen
and comparing postgresql on the same hardware under both Solaris and
Linux.  You'll likely find Postgresql to be about twice as fast under
Linux on Sparc hardware as it is under Solaris.  At least that's what I've
seen.  (My Sparc 20 32 bit machine at 50MHz running Linux easily bested a
150MHz 64 bit Sun Ultra 1 running solaris when benchmarking Postgresql by
about 20 to 50%.)

Also, try Postgresql 7.3b5 which just came out and see how that runs on
both.  There have been some performance improvements that should make both
run faster.