Re: cross table indexes or something? - Mailing list pgsql-performance

From Josh Berkus
Subject Re: cross table indexes or something?
Date
Msg-id 200312011147.51359.josh@agliodbs.com
Whole thread Raw
In response to Re: cross table indexes or something?  (Jeremiah Jahn <jeremiah@cs.earlham.edu>)
Responses Re: cross table indexes or something?  (Jeremiah Jahn <jeremiah@cs.earlham.edu>)
List pgsql-performance
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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