Received: from malur.postgresql.org ([2a02:16a8:dc51::56])
	by arkaria.postgresql.org with esmtps
 (TLS1.2:ECDHE_RSA_AES_256_CBC_SHA384:256)
	(Exim 4.89)
	(envelope-from <pgsql-hackers-owner+archive@lists.postgresql.org>)
	id 1fiLYz-0007R3-3G
	for pgsql-hackers@arkaria.postgresql.org; Wed, 25 Jul 2018 15:18:53 +0000
Received: from localhost ([127.0.0.1] helo=malur.postgresql.org)
	by malur.postgresql.org with esmtp (Exim 4.89)
	(envelope-from <pgsql-hackers-owner+archive@lists.postgresql.org>)
	id 1fiLYx-0001GX-ID
	for pgsql-hackers@arkaria.postgresql.org; Wed, 25 Jul 2018 15:18:51 +0000
Received: from makus.postgresql.org ([2001:4800:1501:1::229])
	by malur.postgresql.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_CBC_SHA384:256)
	(Exim 4.89)
	(envelope-from <andrew@tao11.riddles.org.uk>)
	id 1fiLYx-0001GQ-7p
	for pgsql-hackers@lists.postgresql.org; Wed, 25 Jul 2018 15:18:51 +0000
Received: from lungold.riddles.org.uk ([82.68.208.19])
	by makus.postgresql.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_CBC_SHA384:256)
	(Exim 4.89)
	(envelope-from <andrew@tao11.riddles.org.uk>)
	id 1fiLYt-0004Kt-UP
	for pgsql-hackers@postgresql.org; Wed, 25 Jul 2018 15:18:50 +0000
Received: from [192.168.127.1] (port=26185 helo=caithnard.riddles.org.uk)
	by lungold.riddles.org.uk with esmtps
 (TLSv1.2:ECDHE-RSA-AES256-GCM-SHA384:256)
	(Exim 4.88 (FreeBSD))
	(envelope-from <andrew@tao11.riddles.org.uk>)
	id 1fiLYp-000Ex9-Es; Wed, 25 Jul 2018 15:18:43 +0000
Received: from [127.0.0.1] (port=25897 helo=caithnard.riddles.org.uk)
	by caithnard.riddles.org.uk with esmtp (Exim 4.89 (FreeBSD))
	(envelope-from <andrew@tao11.riddles.org.uk>)
	id 1fiLYo-000JJI-MK; Wed, 25 Jul 2018 15:18:42 +0000
From: Andrew Gierth <andrew@tao11.riddles.org.uk>
To: David Fetter <david@fetter.org>
Cc: pgsql-hackers@postgresql.org
Subject: Re: Early WIP/PoC for inlining CTEs
In-Reply-To: <20180725054236.GB17411@fetter.org> (David Fetter's message of
	"Wed, 25 Jul 2018 07:42:37 +0200")
Message-ID: <87bmavfjhy.fsf@news-spur.riddles.org.uk>
References: <87sh48ffhb.fsf@news-spur.riddles.org.uk>
	<20180725054236.GB17411@fetter.org>
User-Agent: Gnus/5.13 (Gnus v5.13) Emacs/25.1 (berkeley-unix)
Date: Wed, 25 Jul 2018 16:18:42 +0100
MIME-Version: 1.0
Content-Type: text/plain
List-Id: <pgsql-hackers.lists.postgresql.org>
List-Help: <https://lists.postgresql.org/manage/>
List-Subscribe: <https://lists.postgresql.org/manage/>
List-Post: <mailto:pgsql-hackers@lists.postgresql.org>
List-Owner: <mailto:pgsql-hackers-owner@lists.postgresql.org>
List-Archive: <https://www.postgresql.org/list/pgsql-hackers>
Precedence: bulk

>>>>> "David" == David Fetter <david@fetter.org> writes:

 David> Please find attached a version rebased atop 167075be3ab1547e18
 David> with what I believe are appropriate changes to regression test
 David> output. The other changes to the regression tests output are
 David> somewhat puzzling, as they change the actual results of queries.

Both of those changes are the result of volatile CTEs being inlined more
than once (in one case, as part of an explicit test to ensure that CTEs
are being materialized and not multiply evaluated).

If you look for the XXX comment in the patch, it should be easy to add a
check that skips inlining if cterefcount > 1 and
contains_volatile_functions is true.

-- 
Andrew (irc:RhodiumToad)