Horton

Re: Tid scan improvements

Tom Lane <tgl@sss.pgh.pa.us>

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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>
Date: 2019-01-15T03:54:47Z
Lists: pgsql-hackers 
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

Commits

  1. Add TID Range Scans to support efficient scanning ranges of TIDs

  2. Improve planner's selectivity estimates for inequalities on CTID.