From: Justin Pryzby <pryzby@telsasoft.com>
To: Oleksandr Shulgin <oleksandr.shulgin@zalando.de>
Cc: pgsql-performance@lists.postgresql.org
Subject: Re: When to use PARTITION BY HASH?
Date: Wed, 3 Jun 2020 10:09:59 -0500
Message-ID: <20200603150959.GP30144@telsasoft.com> (raw)
In-Reply-To: <CACACo5QUUG0KoTq8uFjtW9Bpqr7d8s=dGDdjxq0R+-YfNs6KPQ@mail.gmail.com>
References: <CACACo5StuUuFox+65KQHB8u+51kMUcEeQuV=XmsUv7d8VnaO7A@mail.gmail.com>
<20200602173353.GB30144@telsasoft.com>
<CACACo5QUUG0KoTq8uFjtW9Bpqr7d8s=dGDdjxq0R+-YfNs6KPQ@mail.gmail.com>
On Wed, Jun 03, 2020 at 09:45:48AM +0200, Oleksandr Shulgin wrote:
> I see. So it works with low cardinality in the partitioned column. With
> high cardinality an index scan on an unpartitioned table would be
> preferable I guess.
>
> The documentation page I've linked only contains examples around
> partitioning BY RANGE. I believe it'd be helpful to extend it with some
> meaningful examples for LIST and HASH partitioning.
I agree. I think it would also be useful to mention the "benefits" which
aren't likely to apply to hash partitioning.
Would you want to propose an example to include ?
Eventually it needs to be submitted as a patch to -hackers.
--
Justin
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To: pgsql-performance@postgresql.org
Cc: pryzby@telsasoft.com, oleksandr.shulgin@zalando.de, pgsql-performance@lists.postgresql.org
Subject: Re: When to use PARTITION BY HASH?
In-Reply-To: <20200603150959.GP30144@telsasoft.com>
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