From: Tom Lane <tgl@sss.pgh.pa.us>
To: "bigbro_wq@hotmail.com" <bigbro_wq@hotmail.com>
cc: pgsql-hackers <pgsql-hackers@lists.postgresql.org>
Subject: Re: Repeat the condition check twice in function distribute_qual_to_rels
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Comments: In-reply-to "bigbro_wq@hotmail.com" <bigbro_wq@hotmail.com>
	message dated "Sun, 03 Nov 2024 14:18:47 +0800"
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Date: Sun, 03 Nov 2024 14:07:02 -0500
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"bigbro_wq@hotmail.com" <bigbro_wq@hotmail.com> writes:
> I notice that check the condtion again when after invoked process_equiva=
lence and return failed.

> 	/* EC rejected it, so set left_ec/right_ec the hard way ... */
> 	if (restrictinfo->mergeopfamilies) /* EC might have changed this */

> Above the codes, check the condition again when invoked process_equivale=
nce failed,
> but it's already under the positive condition "if (restrictinfo->mergeop=
families)".
> It's necessary ?

Yes.  See commit 8ec5429e2: the restrictinfo might now be
completely different from what it was.

(You could have discovered this for yourself by removing
the test and seeing what happened.)

			regards, tom lane