From: Tom Lane <tgl@sss.pgh.pa.us>
To: "David G. Johnston" <david.g.johnston@gmail.com>
cc: Ron <ronljohnsonjr@gmail.com>,
        Pgsql-admin <pgsql-admin@lists.postgresql.org>
Subject: Re: Large number of partitions of a table
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Comments: In-reply-to "David G. Johnston" <david.g.johnston@gmail.com>
	message dated "Mon, 17 Jan 2022 08:14:43 -0700"
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Date: Mon, 17 Jan 2022 10:36:43 -0500
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"David G. Johnston" <david.g.johnston@gmail.com> writes:
> On Mon, Jan 17, 2022 at 7:58 AM Tom Lane <tgl@sss.pgh.pa.us> wrote:
>> Ron <ronljohnsonjr@gmail.com> writes:
>>> I find it hard to believe that you'll *never* run a report against more
>>> customers than are in a single partition.

>> Yeah, I'm a little suspicious of that.

> Is "never" really the correct threshold here?

It is if you've pushed things to the point where, say, "select count(*)
from partitioned_table" will fail outright.  I don't have a lot of faith
in system designs that assume there will never be any ad-hoc queries
that are outside your normal pattern.

			regards, tom lane