Re: Partitioned tables and SELECT ... ORDER BY ... LIMIT - Mailing list pgsql-performance

From François Beausoleil
Subject Re: Partitioned tables and SELECT ... ORDER BY ... LIMIT
Date
Msg-id DB23C183-B0A0-4023-839C-A5EBB34CF1D8@teksol.info
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In response to Partitioned tables and SELECT ... ORDER BY ... LIMIT  (Дмитрий Шалашов <skaurus@gmail.com>)
Responses Re: Partitioned tables and SELECT ... ORDER BY ... LIMIT  (Дмитрий Шалашов <skaurus@gmail.com>)
List pgsql-performance
Hello!

Le 2014-10-16 à 08:35, Дмитрий Шалашов <skaurus@gmail.com> a écrit :
> lets imagine that we have some table, partitioned by timestamp field, and we query it with SELECT with ordering by
thatfield (DESC for example), with some modest limit. 
> Lets further say that required amount of rows is found in the first table that query encounters (say, latest one).
> I am just wondering, why nevertheless PostgreSQL does read couple of buffers from each of the older tables?

Could you share a specific plan with us, as well as your PostgreSQL version? It would make the conversation much
easier.

Can you also confirm your constraint_exclusion parameter is set to either 'partition' or 'on'?

Thanks!
François Beausoleil



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