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 1fqjSZ-0002Ut-Pr for pgsql-performance@arkaria.postgresql.org; Fri, 17 Aug 2018 18:26:55 +0000 Received: from localhost ([127.0.0.1] helo=malur.postgresql.org) by malur.postgresql.org with esmtp (Exim 4.89) (envelope-from ) id 1fqjSX-0000L5-V7 for pgsql-performance@arkaria.postgresql.org; Fri, 17 Aug 2018 18:26:53 +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_SHA384:256) (Exim 4.89) (envelope-from ) id 1fqjSX-0000Kx-Nd for pgsql-performance@lists.postgresql.org; Fri, 17 Aug 2018 18:26:53 +0000 Received: from mail-qk0-x243.google.com ([2607:f8b0:400d:c09::243]) by magus.postgresql.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_CBC_SHA1:256) (Exim 4.89) (envelope-from ) id 1fqjSU-0005Ea-78 for pgsql-performance@lists.postgresql.org; Fri, 17 Aug 2018 18:26:53 +0000 Received: by mail-qk0-x243.google.com with SMTP id p71-v6so1639429qka.9 for ; Fri, 17 Aug 2018 11:26:50 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=2ndquadrant-com.20150623.gappssmtp.com; s=20150623; h=date:from:to:cc:subject:message-id:mime-version:content-disposition :content-transfer-encoding:in-reply-to:user-agent; bh=rkuKojkQ/x60qUjWYsYeY1lYFNU20gGYDMZHQyTa5oI=; b=RJusdMKzn0OR9QaO/c/j5qnlWNZC30UiY3XOqavHP85zqIMkZZeJgwcUHoiBWG6Vu7 qH2wE4oy8Bi0wzlf2gPjm+Jq0i5FwtNFQ8zFRd9XMzoNYKRcpmXZmMh8HTb3RXppDe1d d7TaoSQ72wMFKEuVdkmRh41T0sQHs+98IvvSyIV2kkTpynnBViarWVr0ZIpn0Y/KYuVw RKiRYnABMxKs2/RSdPr56pVmGpkbn1jqcyAyPyoMScG0IXdaBHdh/78aFfMYh6Wl4+HL JFYvLeiDT/ssJoN0iI7i/l+cvi2vqd7fr3S0BtLR87VJRy750uxZvQgwKDhMvIwABKmb HNnA== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:date:from:to:cc:subject:message-id:mime-version :content-disposition:content-transfer-encoding:in-reply-to :user-agent; bh=rkuKojkQ/x60qUjWYsYeY1lYFNU20gGYDMZHQyTa5oI=; b=F4ZvNSEm3WE8hsT0u2b4K10kgwFvOR2DEOTQyQMLYY15WQqmIxJZTS/YpuA3NrtUZ9 4sRH1Em5WWpyiz08DU7zE/CDEGnWRv2DvEMxSUjLwEQK/ALxkAuekt6VY5Kfldfk4xFx WmXO2nAAE8acG1W7ELIpWfcNTLlBTDBCP2kK+i/gBr4LiJvsWZyIDt8LNfh1vJzUo1Th lCZ7JlqjiCXii8Uzhg83z9Eg8/kinHdu8DLgPp/9UrnDg4qbVWBEM6uDiUZodMvVqyZM 6snPq/eVFa3avCKFizbNC2n6oM67MK0B6qezC9N6yrhs4oAK1gaX9V20T2dKnrP15DdK 8ATA== X-Gm-Message-State: AOUpUlErPddAsrDY5N9B2IGUyVyRyDIpXYcV6Gc1oBa3cDU7T4CPge8F qgDeTdCB0Gwtic2nhpnJ/a1lKg== X-Google-Smtp-Source: AA+uWPwyp4lhJiqyurBbZzz8IN3vpc+B2S9RG78O6obKAgkarjBPpExTEpSKiuEvetjLxoWQ7Ag+Zg== X-Received: by 2002:ae9:e118:: with SMTP id g24-v6mr32148440qkm.306.1534530408493; Fri, 17 Aug 2018 11:26:48 -0700 (PDT) Received: from alvin.alvh.no-ip.org ([190.217.216.192]) by smtp.gmail.com with ESMTPSA id e206-v6sm1392171qkb.4.2018.08.17.11.26.47 (version=TLS1_2 cipher=ECDHE-RSA-CHACHA20-POLY1305 bits=256/256); Fri, 17 Aug 2018 11:26:48 -0700 (PDT) Received: by alvin.alvh.no-ip.org (Postfix, from userid 1000) id 9A6665A1; Fri, 17 Aug 2018 15:26:45 -0300 (-03) Date: Fri, 17 Aug 2018 15:26:45 -0300 From: Alvaro Herrera To: Fred Habash Cc: pgsql-performance@lists.postgresql.org Subject: Re: Guideline To Resolve LWLock:SubtransControlLock Message-ID: <20180817182645.nmfaw6w7qzqb2dau@alvherre.pgsql> MIME-Version: 1.0 Content-Type: text/plain; charset=iso-8859-1 Content-Disposition: inline Content-Transfer-Encoding: 8bit In-Reply-To: User-Agent: NeoMutt/20170306-137-4415bd-dirty (1.8.0) List-Id: List-Help: List-Subscribe: List-Post: List-Owner: List-Archive: Precedence: bulk On 2018-Aug-17, Fred Habash wrote: > Aurora Postgres 9.6.3 Oh, okay, I don't know this one. Did you contact Amazon support? > So, no chance to recompile (AFAIK). > Is there a design anti-pattern at the schema or data access level that we > should look for and correct? Maybe ... > And as for the recompile, are you thinking 'NUM_SUBTRANS_BUFFERS'? Yes, that's one option, but there's also TOTAL_MAX_CACHED_SUBXIDS. -- Álvaro Herrera https://www.2ndQuadrant.com/ PostgreSQL Development, 24x7 Support, Remote DBA, Training & Services