Re: Performance tuning?

From: Robert Fitzpatrick <lists(at)webtent(dot)net>
To: Tom Lane <tgl(at)sss(dot)pgh(dot)pa(dot)us>
Cc: PostgreSQL <pgsql-general(at)postgresql(dot)org>
Subject: Re: Performance tuning?
Date: 2007-05-20 00:22:44
Message-ID: 1179620564.10239.26.camel@columbus.webtent.org
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On Sat, 2007-05-19 at 19:19 -0400, Tom Lane wrote:
> You're comparing fields of distinct types, which not only incurs
> run-time type conversions but can interfere with the ability to
> use some plan types at all. Looking at the table definitions,
> you've got primary keys declared as SERIAL (ie, integer) and the
> referencing columns declared as NUMERIC(18,0). This is just horrid
> for
> performance :-( --- NUMERIC arithmetic is pretty slow, and it's really
> pointless when the referenced columns are only integers. I suspect
> you should have translated these column types as BIGINT (and
> BIGSERIAL).

Thanks again, I'll be sure to get this straightened out and tested again
tomorrow. I thought my nightly backup was analyze'ing the database
afterward, I'll be sure to check that as well.

I really appreciate your analysis! It is my first migration from another
SQL database.

--
Robert

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