Re: continuous copy/update one table to another - Mailing list pgsql-general

From Tom Lane
Subject Re: continuous copy/update one table to another
Date
Msg-id 17132.1267457961@sss.pgh.pa.us
Whole thread Raw
In response to Re: continuous copy/update one table to another  (Szymon Guz <mabewlun@gmail.com>)
List pgsql-general
Szymon Guz <mabewlun@gmail.com> writes:
> W dniu 1 marca 2010 09:40 użytkownik Grzegorz Jaśkiewicz
> <gryzman@gmail.com>napisał:
>> don't use 'NOT EXISTS', as this will be damn slow. Use LEFT JOIN.

> Right, LEFT JOIN should be faster (with proper indices even much faster).

Converting NOT EXISTS into an outer join is a manual application of an
optimization that Postgres can do for itself in 8.4 and up.  So the
above advice should only be correct for 8.3 or before.

            regards, tom lane

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