From: Tom Lane <tgl@sss.pgh.pa.us>
To: Robert Haas <robertmhaas@gmail.com>
cc: David Rowley <david.rowley@2ndquadrant.com>,
        Amit Langote <Langote_Amit_f8@lab.ntt.co.jp>,
        Dmitry Dolgov <9erthalion6@gmail.com>,
        Jeff Janes <jeff.janes@gmail.com>,
        Ashutosh Bapat <ashutosh.bapat@enterprisedb.com>,
        Pavel Stehule <pavel.stehule@gmail.com>,
        PostgreSQL Hackers <pgsql-hackers@lists.postgresql.org>
Subject: Re: why partition pruning doesn't work?
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Comments: In-reply-to Robert Haas <robertmhaas@gmail.com>
	message dated "Tue, 12 Jun 2018 12:40:28 -0400"
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Date: Tue, 12 Jun 2018 12:58:42 -0400
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Robert Haas <robertmhaas@gmail.com> writes:
> And there is
> code in RelationClearRelation to avoid changing rd_partkey and
> rd_partdesc if no logical change has occurred.

Oh, and by the way, what's actually in there is

		keep_partkey = (relation->rd_partkey != NULL);

I would be interested to see an explanation of why that isn't utterly
broken.

			regards, tom lane