Re: One Partition by list is always chosen by planner

From: legrand legrand <legrand_legrand(at)hotmail(dot)com>
To: pgsql-general(at)postgresql(dot)org
Subject: Re: One Partition by list is always chosen by planner
Date: 2017-11-22 08:01:34
Message-ID: 1511337694391-0.post@n3.nabble.com
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Hello,

thank you for this answer.
I just wanted to add a few informations.

This table has in fact around 20 partitions,

explain select * from wiki_data_part where category='fr'
returns only 2 partitions (meaning that constraint_exclusion works)

the partition that is always scanned has more than 100 distinct values in
its partition list.

After splitting this partition into 2 partitions the problem is gone ...

For me this is as if the planner was not able to check partitions with too
much values.
There is no error with the query result, just a limited impact on
performances.

Regards
PAscal

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