From: Sean Chittenden <sean@chittenden.org>
To: Josh Berkus <josh@agliodbs.com>
Cc: Christopher Kings-Lynne <chriskl@familyhealth.com.au>
Cc: Nick Barr <nicky@chuckie.co.uk>
Cc: pgsql-performance@postgresql.org
Subject: Re: go for a script! / ex: PostgreSQL vs. MySQL
Date: Mon, 13 Oct 2003 12:10:23 -0700
Message-ID: <20031013191023.GB72842@perrin.nxad.com> (raw)
In-Reply-To: <200310121331.42693.josh@agliodbs.com>
References: <007901c38f2b$0b585590$2802a8c0@webbased10>
<3F8819EF.7010004@chuckie.co.uk>
<3F88BFD7.1020808@familyhealth.com.au>
<200310121331.42693.josh@agliodbs.com>
> > > PostgreSQL requires some more shared memory to cache some
> > > tables, x Mb, do you want to increase your OS kernel parameters?
> > >
> > > Tweak shmmax and shmmall
> >
> > Note that this still requires a kernel recompile on FreeBSD :(
>
> Not our fault, now is it? This would mean that we wouldn't be able
> to script for FreeBSD. Bug the FreeBSD developers.
And if you do so, you're going to hear that shm* is an antiquated
interface that's dated, slow, inefficient and shouldn't be used. :)
Every few months one of the uber core BSD hackers threatens to rewrite
that part of PG because high up in the BSD camp, it's common belief
that shm* is a source of performance loss for PostgreSQL. One of
these days it'll happen, probably with mmap() mmap()'ing MAP_SHARED
files stored in a $PGDATA/data/shared dir as mmap() is by far and away
the fastest shared memory mechanism and certainly is very widely
deployed (I would be surprised if any of the supported PG platforms
didn't have mmap()).
-sc
--
Sean Chittenden
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To: pgsql-performance@postgresql.org
Cc: sean@chittenden.org, josh@agliodbs.com, chriskl@familyhealth.com.au, nicky@chuckie.co.uk
Subject: Re: go for a script! / ex: PostgreSQL vs. MySQL
In-Reply-To: <20031013191023.GB72842@perrin.nxad.com>
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