From: Scott Cain <cain@cshl.org>
To: Tom Lane <tgl@sss.pgh.pa.us>
Cc: PgSQL Performance ML <pgsql-performance@postgresql.org>
Cc: pgsql-sql@postgresql.org
Subject: Re: [SQL] EXTERNAL storage and substring on long strings
Date: 04 Aug 2003 12:25:41 -0400
Message-ID: <1060014341.1434.53.camel@localhost.localdomain> (raw)
In-Reply-To: <3574.1060012423@sss.pgh.pa.us>
References: <1059679600.1429.41.camel@localhost.localdomain>
<3F297CBA.1080703@joeconway.com>
<1059686498.7505.558.camel@haggis>
<1060010735.1433.26.camel@localhost.localdomain>
<3574.1060012423@sss.pgh.pa.us>
On Mon, 2003-08-04 at 11:53, Tom Lane wrote:
> Scott Cain <cain@cshl.org> writes:
> > At least this appears to work and is much faster, completing substring
> > operations like above in about 0.27 secs (that's about two orders of
> > magnitude improvement!)
>
> I find it really, really hard to believe that a crude reimplementation
> in plpgsql of the TOAST concept could beat the built-in implementation
> at all, let alone beat it by two orders of magnitude.
>
> Either there's something unrealistic about your testing of the
> dna_string function, or your original tests are not causing TOAST to be
> invoked in the expected way, or there's a bug we need to fix. I'd
> really like to see some profiling of the poor-performing
> external-storage case, so we can figure out what's going on.
>
I was really hoping for a "Good job and glad to hear it" from you :-)
I don't think there is anything unrealistic about my function or its
testing, as it is very much along the lines of the types of things we do
now. I will really try to do some profiling this week to help figure
out what is going on.
Scott
--
------------------------------------------------------------------------
Scott Cain, Ph. D. cain@cshl.org
GMOD Coordinator (http://www.gmod.org/) 216-392-3087
Cold Spring Harbor Laboratory
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Reply to all the recipients using the --to and --cc options:
reply via email
To: pgsql-sql@postgresql.org
Cc: cain@cshl.org, tgl@sss.pgh.pa.us, pgsql-performance@postgresql.org
Subject: Re: [SQL] EXTERNAL storage and substring on long strings
In-Reply-To: <1060014341.1434.53.camel@localhost.localdomain>
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
This inbox is served by DDX for PostgreSQL; see mirroring instructions
for how to clone and mirror all data and code used for this inbox