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 1hUXWs-000201-7p for pgsql-performance@arkaria.postgresql.org; Sat, 25 May 2019 14:20:10 +0000 Received: from localhost ([127.0.0.1] helo=malur.postgresql.org) by malur.postgresql.org with esmtp (Exim 4.89) (envelope-from ) id 1hUXWq-0004Fo-66 for pgsql-performance@arkaria.postgresql.org; Sat, 25 May 2019 14:20:08 +0000 Received: from makus.postgresql.org ([2001:4800:3e1:1::229]) by malur.postgresql.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_CBC_SHA1:256) (Exim 4.89) (envelope-from ) id 1hUXWp-0004Dp-Q9 for pgsql-performance@lists.postgresql.org; Sat, 25 May 2019 14:20:07 +0000 Received: from wout5-smtp.messagingengine.com ([64.147.123.21]) by makus.postgresql.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_CBC_SHA1:256) (Exim 4.89) (envelope-from ) id 1hUXWm-0004He-5T for pgsql-performance@lists.postgresql.org; Sat, 25 May 2019 14:20:06 +0000 Received: from compute7.internal (compute7.nyi.internal [10.202.2.47]) by mailout.west.internal (Postfix) with ESMTP id 48817379; Sat, 25 May 2019 10:20:02 -0400 (EDT) Received: from mailfrontend2 ([10.202.2.163]) by compute7.internal (MEProxy); Sat, 25 May 2019 10:20:02 -0400 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d= messagingengine.com; h=content-transfer-encoding:content-type :date:from:in-reply-to:message-id:mime-version:references :subject:to:x-me-proxy:x-me-proxy:x-me-sender:x-me-sender :x-sasl-enc; s=fm2; bh=qTXYz3OlBsrMTxi01hANfh5/vUHi2mWC3HiSTzuLA ts=; b=vHb40M9yt6uqdVXfB6u0jYQH1Ciu1nEoB7XEwXRN6ar3GVLMAYpGeYr1C 8Lrsl+eed930sSLA82O+ElK21a7Nk+jwaqz1qLSU5tTHGP1Po8KWEhfSX2pY7CUe 6Wd1b/0vut1OURdRIG7DbmrlMt6QuLJn2ONTwtbpjJ968mZmJIrq0fItK8Daew0n z5zANBojcPZ3sTAZAZaLe72iF/h4DmW/A+o8xuiWLynq0UnSjkwtdqlMNakTSytB EpmrcwQAuffkTLzSrMxvuxYLWbbYl7fDwVArRF+JBKHEKHSlpWLhs6077tDgKAta JQlMJ3tQDdleHJmBy09JOm1v1R38w== X-ME-Sender: X-ME-Proxy-Cause: gggruggvucftvghtrhhoucdtuddrgeduuddruddukedgjeejucetufdoteggodetrfdotf fvucfrrhhofhhilhgvmecuhfgrshhtofgrihhlpdfqfgfvpdfurfetoffkrfgpnffqhgen uceurghilhhouhhtmecufedttdenucesvcftvggtihhpihgvnhhtshculddquddttddmne cujfgurhepuffvfhfhohfkffgfgggjtgfgsehtjeertddtfeejnecuhfhrohhmpefrvght vghrucfgihhsvghnthhrrghuthcuoehpvghtvghrrdgvihhsvghnthhrrghuthesvdhnug hquhgrughrrghnthdrtghomheqnecuffhomhgrihhnpedvnhguqhhurggurhgrnhhtrdgt ohhmnecukfhppeelfedrvdegvddruddvuddrudduleenucfrrghrrghmpehmrghilhhfrh homhepphgvthgvrhdrvghishgvnhhtrhgruhhtsedvnhguqhhurggurhgrnhhtrdgtohhm necuvehluhhsthgvrhfuihiivgeptd X-ME-Proxy: Received: from april.pezone.net (p5df27977.dip0.t-ipconnect.de [93.242.121.119]) by mail.messagingengine.com (Postfix) with ESMTPA id 8F0EF380089; Sat, 25 May 2019 10:20:00 -0400 (EDT) Subject: Re: UUID v1 optimizations... To: Ancoron Luciferis , pgsql-performance@lists.postgresql.org References: <8d5f4b67-d540-8d3d-9979-808b9c1e1ca7@googlemail.com> From: Peter Eisentraut Openpgp: preference=signencrypt Autocrypt: addr=peter.eisentraut@2ndquadrant.com; prefer-encrypt=mutual; keydata= xsFNBFUUt6kBEADZd9NNTBJbHmAXXJgPGOdd6Q73l80oifIVgn2tRxP9dYkCfTlo/yLqbKTl JNqTcyM6XrJDnB2sMEUGYCewYZXl+9C4bBJWyNqcEI1ae9u71vEq/fknFLArJ+2wN+f7QuRx Q8d94ZJAiJQ5g3fNk2HVeedCQCKP5dCzU+ZLt2dbsx1PDZLjTO9gf+JswWuGFb5wY5PZVM5V hq66Xk7ZJzHuARacza2RT7J2fkMmQBY+kr7L98Perb0GhafnlhXB0PvUB+N3xpmggMfwuhTu BngS/G/r3GvemxJuFxouw8xsMqrsfdksJXA2gLXYtwRCssdPV3PO0rlD9twqDo8URfIJ5fb6 1g/MV8aTOKjg3Q8MpJPtkwJqN4o3PvbwYdedeFnOVkkYAJdu/aX1v1BeCBDu7Hy3sF52scD3 pQbyQSl9vUDpTLarASAxNbAV0NRJE8dp4vfW6AH1ccryGiFqw/czPK/iN0+MT8wsjAW6WW4w hvjm5UPA1KTwi3ZT8eT5uycuH7QpuNk7LnGGXQ6KaRALFywzkr0A0V0AvFNa+l4wstMaXaB6 dmMXyF0/hfryqyOeu1gAdq4q0/PNC2dPgb/6uoh4eMjN6A5GXcprilhz5DulmsilY21hfSoU S64ODed96pKhprsOxjZiDRsN1QM5MwB+uwVWUNfsX7fIxE0BrwARAQABzSdQZXRlciBFaXNl bnRyYXV0IDxwZXRlckBlaXNlbnRyYXV0Lm9yZz7CwXoEEwEIACQCGwMFCwkIBwMFFQoJCAsF FgIDAQACHgECF4AFAlUUuKQCGQEACgkQoZ8SQ+xBJp8llw//RbGoXnF72FZTlOFsnNyxnWbF vViPCfdAlZl1GGK9OYCvV1dp/956HuhB0wpaGQHiBmQfOPJf/jLOPjXFYm2iEChEycrBChuE j4TSYemMp5BSPILYk9Uwd16kVD/+U6fQfK6H5pOhfBvbM6asMnmpY2wQuvktxHvaGlytFw84 EzFWNZtAZfxkw28w3AhIQkKe9hJanfyDL750RcbyEr8AAHty5IErrvS7tM5vQwIeh5BF26ND CyKPRdZgOgMpcwFfROKBDpAt052CgWIpNdhBdfIKlkCs4/ILxmC3rT/Mb/qZiHcoMMwEu6k+ T7vRAFZZAk62Yrr/U8/vUGKlzRZQoo86fyojCfI0ibCIc0z8rwCVY9P40G9wD9BTCZS/z8Vh jjpBlNnIKw2hM6hbxavKndCJjFFJD08rXrTyrLF/of18xD37vNdYooP9VATB5QjOWFRrscSZ 4a89e+to3m7YVnd4xdXwGp47dYusoax84C8tg1gZrH38ol9dPmnKX6GZrXeS7tH9k8VeUpJ8 HQbRThQRWAT936QpYbLConBmOtmbLmjQOGtiXPo1oK57X/7U/WBja5vWmm2q+Yxtt+3uHGVg DdDU4CJpXo4lX0v2n3QV5EBSW9hjdF3bNfl6GFBb1pPEhqNcMDUc7zkx/2uENdAdk/BnqMgH umip7b0pVfvOwU0EVRS3qQEQAJf6p0P7D+hMYUgCPkvgrcz6OJYsAYdUMUmokfqmkKwK0oJM ew8TNGM53ocKAgQGma5f10rwbZNPlpVPNRX5hwUmwVlcwSut0oE+JfUBH7mpysWvpF05RKIy q9RCoJZrAbXS7Tig56A1QD8IcM00rERZMcCOlI1+q9m4u9AOI+0LyGGSH+VvoyDHD/Jew4R2 TmPEF8Pu7lYiNYK88Q6u0kBkc+Tz3BNlyc6fi3HxnFfp0b75HLXPSTu2SwA/0Q31wHZXwrEU BR9KgSn/qbgy8ydPc97i82fhiFE3cbGexfPrQSMYmDGi+dcQ0s+AMQwC3XyMC0JkHpYUuFkR QdlIvaIhgFUUN2Vr4xF2ADaNTNFc4DYaiPHFAgHZw+3pZWqS4uIiWgJynrEaHw4F3QWU8/JB iyEWDhNq4WBrRA0u914TCCAoFOOKMnRdl8eJrRQKM/5/lXbHFjjlI/LDKhLRFsuQsnJJ3331 RjCzpHPZG5/p5KR1RHiAXa0p/DW5lXyq21hS3kjDlleoHqOxCN/cy0Jgz7qLDq1vZoCl67Sy RAH60c2Xu4may9SVltmot0OzWVHdrfS+85FQGp9580DaeLio7YMFKy2bfEvwQJ/c9xD2QPB+ oSb3V8ueSznXBG5+dyfOsZFRPxceA0wA2rSWZSjxLdKxvyGTj9vsCjaDu13rABEBAAHCwV8E GAEIAAkFAlUUt6kCGwwACgkQoZ8SQ+xBJp+HJhAAxmSTsC5y7p9Zu+nnLpucv/h88oEx985e qWeXzQiwM3pfRZS+PdTH9TyzHK0KOgKoAiubk0vt+BrT91D9d0G5kVQaTctAErGBoMkTaZJT XVEcNphiPzysdSqvprjojMp1y7rG8AP+Xd6m0rE1LRnkRRm8HyI8vdXsuLQPITGWXDLMjaNq AOV3BUnzkgtjMuIYw7SCr+12ZOb5dEKvaG4kjC4kaJ/TLbuBhVANcXkC90yp0AOZLs/cB1Dj OAXno/RUUruJ3r27a+pFv768UAi9QWcdw58yPxreMNMLqAgsS9oTHwHfGNWcB2dJ4UW+GMLJ hTf9TjQ2f+N/sIx5XMQ9pYw6CAJMK29qPx6/ZayrPxf22EXf0D3zTwIEZgwfSkynFVwV25L7 awQq60fifdMYheSxq7GbhpsixmcD+e161cCmLIt75YDt5bQ0B1yf7EmxG8n7pGZAOM6LoNsU fkSldba5XVwh8LuN5mK0nQBELGW6Os4TDq4REggLpfcvFC215zpuo0iCGnmE/Bns4nowqUSP u4tkWL+nxW4qgv8wo8HJ52jd79EJ8iqfIBoidBfy9AIUiEUApGQzWPu6yWcI8fY0rN5D+tc+ Yw1Zt6Mm+huYJpgCRsTcfzEcahnBn521CWcWvhW1ff3KFileFMtNmnBBhMncmRKHphtTKEpN 3jI= Organization: 2ndQuadrant Message-ID: <6099cb7d-3507-9b01-433d-dc709ecec8ed@2ndquadrant.com> Date: Sat, 25 May 2019 16:19:59 +0200 User-Agent: Mozilla/5.0 (Macintosh; Intel Mac OS X 10.14; rv:52.0) Gecko/20100101 Thunderbird/52.9.1 MIME-Version: 1.0 In-Reply-To: <8d5f4b67-d540-8d3d-9979-808b9c1e1ca7@googlemail.com> Content-Type: text/plain; charset=utf-8 Content-Language: en-US Content-Transfer-Encoding: 7bit List-Id: List-Help: List-Subscribe: List-Post: List-Owner: List-Archive: Precedence: bulk On 2019-05-25 15:45, Ancoron Luciferis wrote: > So, my question now is: Would it make sense for you to handle these > time-based UUID's differently internally? Specifically un-shuffling the > timestamp before they are going to storage? It seems unlikely that we would do that, because that would break existing stored UUIDs, and we'd also need to figure out a way to store non-v1 UUIDs under this different scheme. The use case is pretty narrow compared to the enormous effort. It is well understood that using UUIDs or other somewhat-random keys perform worse than serial-like keys. Btw., it might be nice to rerun your tests with PostgreSQL 12beta1. The btree storage has gotten some improvements. I don't think it's going to fundamentally solve your problem, but it would be useful feedback. -- Peter Eisentraut http://www.2ndQuadrant.com/ PostgreSQL Development, 24x7 Support, Remote DBA, Training & Services