References: <17540-7aa1855ad5ec18b4@postgresql.org>
 <CAApHDvqRR81Dvur_zcrY+RsKxv_e8uDpJ2xxAPMmnfgDY7VNew@mail.gmail.com>
 <2732256.1657163219@sss.pgh.pa.us>
 <CAApHDvqhr1eU9v42w5gt_gL=G15pB9RBpAH_Jmg7eDU6iZ_2zg@mail.gmail.com>
 <2740652.1657165848@sss.pgh.pa.us>
 <CAApHDvqHCNKJi9CrQZG-reQDXTfRWnT5rhzNtDQhnrBzAAusfA@mail.gmail.com>
 <CAMbWs48fiio5RcsBHztjNXXYvU4QKTekbszECs0ydpY2faqo9A@mail.gmail.com>
 <CAMbWs49E2Ps7xdPNTAQOuDg6B9RAidcgQ2S4_nEdveSg_GqiDg@mail.gmail.com>
 <CAApHDvr+70jEZpraMZ8sj=UH77dBzCaeUc9EcJHB3YaxX9syNg@mail.gmail.com>
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 <CAMbWs4-eNVNTNc94eF+O_UwHYKv43vyMurhcdqMV=Ht5fehcOg@mail.gmail.com>
 <74a806ed-3b6c-4c45-a67a-27b5f3496ae5@postgrespro.ru>
 <CAMbWs4-zYenAVp-fmgtvBtWKoauL8gBqUHctP6rOmny5Ox8SkA@mail.gmail.com>
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User-agent: mu4e 1.10.7; emacs 29.1
From: Andy Fan <zhihuifan1213@163.com>
To: David Rowley <dgrowleyml@gmail.com>
Cc: Richard Guo <guofenglinux@gmail.com>, Andrei Lepikhov
 <a.lepikhov@postgrespro.ru>, Tom Lane <tgl@sss.pgh.pa.us>,
 pgsql-hackers@lists.postgresql.org
Subject: Re: Removing const-false IS NULL quals and redundant IS NOT NULL
 quals
Date: Wed, 27 Dec 2023 19:20:38 +0800
In-reply-to: 
 <CAApHDvqg6XZDhYRPz0zgOcevSMo0d3vxA9DvHrZtKfqO30WTnw@mail.gmail.com>
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Hi,

David Rowley <dgrowleyml@gmail.com> writes:

>
> Happy to hear other people's thoughts on this patch.  Otherwise, I
> currently don't think the missed optimisation is a reason to block
> what we've ended up with so far.
>
> David
>
> [1] https://postgr.es/m/flat/17540-7aa1855ad5ec18b4%40postgresql.org
>
> [2. application/x-patch; v10-0001-Reduce-NullTest-quals-to-constant-TRUE-or-FALSE.patch]...

Thanks for working on this, an I just get a complaint about this missed
optimisation 7 hours ago..

I also want to add notnullattnums for the UniqueKey stuff as well, by
comparing your implementation with mine,  I found you didn't consider
the NOT NULL generated by filter. After apply your patch:

create table a(a int);
explain (costs off) select * from a where a > 3 and a is null;
             QUERY PLAN              
-------------------------------------
 Seq Scan on a
   Filter: ((a IS NULL) AND (a > 3))
(2 rows)

This is acutally needed by UniqueKey stuff, do you think it should be
added? To save some of your time, you can check what I did in UniqueKey

[1]
https://www.postgresql.org/message-id/attachment/151254/v1-0001-uniquekey-on-base-relation-and-used-it-for-mark-d.patch 
-- 
Best Regards
Andy Fan