Received: from malur.postgresql.org ([217.196.149.56]) by arkaria.postgresql.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_CBC_SHA1:256) (Exim 4.89) (envelope-from ) id 1gcCCq-0006MS-3c for pgsql-hackers@arkaria.postgresql.org; Wed, 26 Dec 2018 16:38:52 +0000 Received: from localhost ([127.0.0.1] helo=malur.postgresql.org) by malur.postgresql.org with esmtp (Exim 4.89) (envelope-from ) id 1gcCCo-00042M-Pu for pgsql-hackers@arkaria.postgresql.org; Wed, 26 Dec 2018 16:38:50 +0000 Received: from magus.postgresql.org ([2a02:c0:301:0:ffff::29]) by malur.postgresql.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_CBC_SHA1:256) (Exim 4.89) (envelope-from ) id 1gcCCo-00042F-Ik for pgsql-hackers@lists.postgresql.org; Wed, 26 Dec 2018 16:38:50 +0000 Received: from xvm-110-146.dc2.ghst.net ([46.226.110.146] helo=fetter.org) by magus.postgresql.org with esmtp (Exim 4.89) (envelope-from ) id 1gcCCh-0004t2-IT for pgsql-hackers@postgresql.org; Wed, 26 Dec 2018 16:38:50 +0000 Received: by fetter.org (Postfix, from userid 1001) id 9D34D41C49; Wed, 26 Dec 2018 17:38:41 +0100 (CET) Date: Wed, 26 Dec 2018 17:38:41 +0100 From: David Fetter To: Tom Lane Cc: Robert Haas , Andres Freund , Andrew Gierth , John Naylor , "pgsql-hackers@postgresql.org" Subject: Re: reducing the footprint of ScanKeyword (was Re: Large writable variables) Message-ID: <20181226163840.GE416@fetter.org> References: <25160.1545086368@sss.pgh.pa.us> <31505.1545149557@sss.pgh.pa.us> <87lg4luimz.fsf@news-spur.riddles.org.uk> <20181220010114.k3wv6r25sc7sr7z5@alap3.anarazel.de> <28725.1545841359@sss.pgh.pa.us> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <28725.1545841359@sss.pgh.pa.us> User-Agent: Mutt/1.9.4 (2018-02-28) List-Id: List-Help: List-Subscribe: List-Post: List-Owner: List-Archive: Precedence: bulk On Wed, Dec 26, 2018 at 11:22:39AM -0500, Tom Lane wrote: > > In my hands, the only part of the low-level parsing code that > commonly shows up as interesting in profiles is the Bison engine. Should we be considering others? As I understand it, steps have been made in this field since yacc was originally designed. Is LALR actually suitable for languages like SQL, or is it just there for historical reasons? Best, David. -- David Fetter http://fetter.org/ Phone: +1 415 235 3778 Remember to vote! Consider donating to Postgres: http://www.postgresql.org/about/donate