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	Mon, 14 Jan 2019 22:54:47 -0500
From: Tom Lane <tgl@sss.pgh.pa.us>
To: Edmund Horner <ejrh00@gmail.com>
cc: David Rowley <david.rowley@2ndquadrant.com>,
        Tomas Vondra <tomas.vondra@2ndquadrant.com>,
        PostgreSQL Developers <pgsql-hackers@lists.postgresql.org>
Subject: Re: Tid scan improvements
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Comments: In-reply-to Edmund Horner <ejrh00@gmail.com>
	message dated "Tue, 15 Jan 2019 16:47:09 +1300"
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Edmund Horner <ejrh00@gmail.com> writes:
> On Sat, 22 Dec 2018 at 07:10, Tom Lane <tgl@sss.pgh.pa.us> wrote:
>> I'm not entirely sure why you're bothering; surely nulltestsel is
>> unrelated to what this patch is about?

> I found that it made a difference with selectivity of range comparisons,
> because clauselist_selectivity tries to correct for it (clausesel.c:274):

Oh, I see.

> I guess we could have a standalone patch to add this for all system columns?

+1

			regards, tom lane