Re: help on a query - Mailing list pgsql-sql

From Greg Stark
Subject Re: help on a query
Date
Msg-id 87sm8o4m25.fsf@stark.xeocode.com
Whole thread Raw
In response to Re: help on a query  (Michelle Murrain <tech@murrain.net>)
List pgsql-sql
Michelle Murrain <tech@murrain.net> writes:

> The OUTER JOIN version is quite a bit more efficient (by an order of magnitude)
> than the option with WHERE NOT EXISTS subquery.

This is going to be heavily dependent on the version of postgres. IN/NOT IN
execution has improved a lot in 7.4 and later. If you're still on 7.3 then the
outer join will be better. But in 7.4 I would actually expect the NOT IN or
the NOT EXISTS to be faster.

-- 
greg



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