| From: | François Beausoleil <francois(at)teksol(dot)info> |
|---|---|
| To: | Дмитрий Шалашов <skaurus(at)gmail(dot)com> |
| Cc: | "pgsql-performance(at)postgresql(dot)org" <pgsql-performance(at)postgresql(dot)org> |
| Subject: | Re: Partitioned tables and SELECT ... ORDER BY ... LIMIT |
| Date: | 2014-10-16 13:19:12 |
| Message-ID: | DB23C183-B0A0-4023-839C-A5EBB34CF1D8@teksol.info |
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| Lists: | pgsql-performance |
Hello!
Le 2014-10-16 à 08:35, Дмитрий Шалашов <skaurus(at)gmail(dot)com> a écrit :
> lets imagine that we have some table, partitioned by timestamp field, and we query it with SELECT with ordering by that field (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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