Received: from malur.postgresql.org ([217.196.149.56]) by arkaria.postgresql.org with esmtp (Exim 4.84_2) (envelope-from ) id 1eYx4c-0002wl-0y for pgsql-docs@arkaria.postgresql.org; Tue, 09 Jan 2018 16:48:26 +0000 Received: from localhost ([127.0.0.1] helo=malur.postgresql.org) by malur.postgresql.org with esmtp (Exim 4.84_2) (envelope-from ) id 1eYx4b-0001sK-IQ for pgsql-docs@arkaria.postgresql.org; Tue, 09 Jan 2018 16:48:25 +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 4.84_2) (envelope-from ) id 1eYx4b-0001sA-9s for pgsql-docs@lists.postgresql.org; Tue, 09 Jan 2018 16:48:25 +0000 Received: from smtprelay0094.b.hostedemail.com ([64.98.42.94] helo=smtprelay.b.hostedemail.com) by makus.postgresql.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_CBC_SHA384:256) (Exim 4.89) (envelope-from ) id 1eYx4Y-0001Fh-GR for pgsql-docs@postgresql.org; Tue, 09 Jan 2018 16:48:24 +0000 Received: from filter.hostedemail.com (10.5.19.248.rfc1918.com [10.5.19.248]) by smtprelay01.b.hostedemail.com (Postfix) with ESMTP id 3EA2B2D2CE1; Tue, 9 Jan 2018 16:47:39 +0000 (UTC) X-Session-Marker: 616C76686572726540616C76682E6E6F2D69702E6F7267 X-Spam-Summary: 50,0,0,,d41d8cd98f00b204,alvherre@alvh.no-ip.org,:::,RULES_HIT:41:355:379:599:967:973:988:989:1260:1277:1311:1312:1313:1314:1345:1359:1437:1515:1516:1518:1519:1534:1538:1593:1594:1595:1596:1711:1714:1730:1747:1777:1792:2393:2525:2560:2563:2682:2685:2828:2859:2933:2937:2939:2942:2945:2947:2951:2954:3022:3138:3139:3140:3141:3142:3351:3743:3865:3866:3867:3868:3870:3871:3872:3873:3874:3934:3936:3938:3941:3944:3947:3950:3953:3956:3959:4605:5007:6119:6261:7903:8527:8957:9025:9121:10004:10400:10848:11232:11658:11914:13069:13163:13229:13311:13357:13439:13894:13895:14516:14764:21080:21627:30054:30070,0,RBL:none,CacheIP:none,Bayesian:0.5,0.5,0.5,Netcheck:none,DomainCache:0,MSF:not bulk,SPF:,MSBL:0,DNSBL:none,Custom_rules:0:0:0,LFtime:2,LUA_SUMMARY:none X-HE-Tag: hope06_42bf14eaa0555 X-Filterd-Recvd-Size: 1392 Received: from alvin.alvh.no-ip.org (unknown [179.57.113.18]) (Authenticated sender: alvherre@alvh.no-ip.org) by omf14.b.hostedemail.com (Postfix) with ESMTPA; Tue, 9 Jan 2018 16:47:38 +0000 (UTC) Received: by alvin.alvh.no-ip.org (Postfix, from userid 1000) id E3C6B880; Tue, 9 Jan 2018 13:47:35 -0300 (-03) Date: Tue, 9 Jan 2018 13:47:35 -0300 From: Alvaro Herrera To: Brian McKiernan Cc: pgsql-docs@postgresql.org Subject: Re: Advice on Contiguous IDs Message-ID: <20180109164735.ic7pmtxehekv7paf@alvherre.pgsql> MIME-Version: 1.0 Content-Type: text/plain; charset=iso-8859-1 Content-Disposition: inline Content-Transfer-Encoding: 8bit In-Reply-To: <5a546fcab6ae2e0000bdb8e4@polymail.io> User-Agent: NeoMutt/20170306-137-4415bd-dirty (1.8.0) List-Id: List-Help: List-Subscribe: List-Post: List-Owner: List-Archive: Precedence: bulk Brian McKiernan wrote: > My Issue: > My primary keys in a certain table are not contiguous. If you have a need to have values that are contiguous, you need to ask yourself why and then see what mechanism provides the semantics you need. An easy way is to lock the table containing the column, for example, which of course means only one transaction can do it at a time. For many use cases this is good enough. -- Álvaro Herrera https://www.2ndQuadrant.com/ PostgreSQL Development, 24x7 Support, Remote DBA, Training & Services