Re: cross table indexes or something?

From: Josh Berkus <josh(at)agliodbs(dot)com>
To: Jeremiah Jahn <jeremiah(at)cs(dot)earlham(dot)edu>, Hannu Krosing <hannu(at)tm(dot)ee>
Cc: postgres performance <pgsql-performance(at)postgresql(dot)org>
Subject: Re: cross table indexes or something?
Date: 2003-12-01 19:47:51
Message-ID: 200312011147.51359.josh@agliodbs.com
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Jeremiah,

> I've attached the Analyze below. I have no idea why the db thinks there
> is only 1 judge named simth. Is there some what I can inform the DB
> about this. In actuality, there aren't any judges named smith at the
> moment, but there are 22K people named smith.

No, Hannu meant that you may need to run the following command:

ANALYZE actor;

... to update the database statistics on the actors table. That is a
maintainence task that needs to be run periodically.

If that doesn't fix the bad plan, then the granularity of statistics on the
full_name column needs updating; I suggest:

ALTER TABLE actor ALTER COLUMN full_name SET STATISTICS 100;
ANALYZE actor;

And if it's still choosing a slow nested loop, up the stats to 250.

--
Josh Berkus
Aglio Database Solutions
San Francisco

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