From: Simon Riggs <simon@2ndquadrant.com>
To: Dan Harris <fbsd@drivefaster.net>
Cc: pgsql-performance@postgresql.org
Subject: Re: Quad Opteron stuck in the mud
Date: Wed, 13 Jul 2005 23:51:16 +0100
Message-ID: <1121295076.3970.381.camel@localhost.localdomain> (raw)
In-Reply-To: <E5E21B7B-FFE0-4D24-8CDD-62179AEBBB92@drivefaster.net>
References: <E5E21B7B-FFE0-4D24-8CDD-62179AEBBB92@drivefaster.net>
On Wed, 2005-07-13 at 12:54 -0600, Dan Harris wrote:
> For example, as I'm writing this, I am running an UPDATE statement
> that will affect a small part of the table, and is querying on an
> indexed boolean field.
An indexed boolean field?
Hopefully, ftindex is false for very few rows of the table?
Try changing the ftindex to be a partial index, so only index the false
values. Or don't index it at all.
Split the table up into smaller pieces.
Don't use an UPDATE statement. Keep a second table, and insert records
into it when you would have updated previously. If a row is not found,
you know that it has ftindex=true. That way, you'll never have row
versions building up in the main table, which you'll still get even if
you VACUUM.
Best Regards, Simon Riggs
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To: pgsql-performance@postgresql.org
Cc: simon@2ndquadrant.com, fbsd@drivefaster.net
Subject: Re: Quad Opteron stuck in the mud
In-Reply-To: <1121295076.3970.381.camel@localhost.localdomain>
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