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 ) id 1g7l87-0001Ak-Mb for pgsql-hackers@arkaria.postgresql.org; Wed, 03 Oct 2018 17:40:11 +0000 Received: from localhost ([127.0.0.1] helo=malur.postgresql.org) by malur.postgresql.org with esmtp (Exim 4.89) (envelope-from ) id 1g7l86-0000lT-3m for pgsql-hackers@arkaria.postgresql.org; Wed, 03 Oct 2018 17:40:10 +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 ) id 1g7l85-0000lJ-P2 for pgsql-hackers@lists.postgresql.org; Wed, 03 Oct 2018 17:40:09 +0000 Received: from sss.pgh.pa.us ([66.207.139.130]) by makus.postgresql.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_CBC_SHA384:256) (Exim 4.89) (envelope-from ) id 1g7l83-0007CA-ED for pgsql-hackers@lists.postgresql.org; Wed, 03 Oct 2018 17:40:08 +0000 Received: from sss1.sss.pgh.pa.us (localhost [127.0.0.1]) by sss.pgh.pa.us (8.14.4/8.14.4) with ESMTP id w93He37Q002436; Wed, 3 Oct 2018 13:40:03 -0400 From: Tom Lane To: Andres Freund cc: pgsql-hackers@lists.postgresql.org, Thomas Munro , Andrew Gierth , Alexander Kuzmenkov Subject: Re: Performance improvements for src/port/snprintf.c In-reply-to: <20181003173639.tncawup2nnkp7vbv@alap3.anarazel.de> References: <20181003060936.zul7mfkcu5w7rotg@alap3.anarazel.de> <25583.1538569214@sss.pgh.pa.us> <20181003155207.b3lqmovuv2c5c4id@alap3.anarazel.de> <26510.1538582852@sss.pgh.pa.us> <20181003161454.ozeioucsimjg5g6m@alap3.anarazel.de> <27041.1538583733@sss.pgh.pa.us> <20181003163717.oycshpp2hnctvtfj@alap3.anarazel.de> <28321.1538585692@sss.pgh.pa.us> <20181003170043.thdyezozi343dkuc@alap3.anarazel.de> <2132.1538587869@sss.pgh.pa.us> <20181003173639.tncawup2nnkp7vbv@alap3.anarazel.de> Comments: In-reply-to Andres Freund message dated "Wed, 03 Oct 2018 10:36:39 -0700" MIME-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-ID: <2434.1538588403.1@sss.pgh.pa.us> Date: Wed, 03 Oct 2018 13:40:03 -0400 Message-ID: <2435.1538588403@sss.pgh.pa.us> List-Id: List-Help: List-Subscribe: List-Post: List-Owner: List-Archive: Precedence: bulk Andres Freund writes: > On 2018-10-03 13:31:09 -0400, Tom Lane wrote: >> I do not see the point of messing with snprintf.c here. I doubt that >> strfromd is faster than the existing sprintf call (because the latter >> can use ".*" instead of serializing and deserializing the precision). > I'm confused, the numbers I posted clearly show that it's faster? Those were in the context of whether float8out went through snprintf.c or directly to strfromd, no? regards, tom lane