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 1hcgxt-0000bN-J8 for pgsql-performance@arkaria.postgresql.org; Mon, 17 Jun 2019 02:01:45 +0000 Received: from localhost ([127.0.0.1] helo=malur.postgresql.org) by malur.postgresql.org with esmtp (Exim 4.89) (envelope-from ) id 1hcgxs-0003t5-CP for pgsql-performance@arkaria.postgresql.org; Mon, 17 Jun 2019 02:01:44 +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 1hcgxs-0003sy-3d for pgsql-performance@lists.postgresql.org; Mon, 17 Jun 2019 02:01:44 +0000 Received: from wout5-smtp.messagingengine.com ([64.147.123.21]) by magus.postgresql.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_CBC_SHA1:256) (Exim 4.89) (envelope-from ) id 1hcgxl-0000Dk-Gx for pgsql-performance@lists.postgresql.org; Mon, 17 Jun 2019 02:01:43 +0000 Received: from compute4.internal (compute4.nyi.internal [10.202.2.44]) by mailout.west.internal (Postfix) with ESMTP id 6A670434; Sun, 16 Jun 2019 22:01:33 -0400 (EDT) Received: from mailfrontend1 ([10.202.2.162]) by compute4.internal (MEProxy); Sun, 16 Jun 2019 22:01:33 -0400 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=paquier.xyz; h= date:from:to:cc:subject:message-id:references:mime-version :content-type:in-reply-to; s=fm2; bh=AJY6slB3E5b7La1Cr310C+dTZNs fWp+yQ4nl3p7aaRU=; b=wWSC0JqIibr1IY4GS4SIGPBMi/eHG+Ndl2lrENJwV2q PJVX9EJuQU6/gjjEpWk2oW/XnnpbuxXnBVVIf27gh51x37zkribYErHfmFZeYHoj 8GzoLjJI036PUDlYbBfILNp1fJEChDozmpz1JgUgiUxT3ysABAH8nU6rPl4Zvi9/ SxPv26WlkQIsAvkN0i84CgMM54NUXJgw9syGHYtSK9rpymB2Ny6FxHzv0WaSsPop 90rOHDnGlsnu2UUwRaMvboeQ7Q/YpuLz8ytdAMS6jAuqtWguxzVfue/7o287MMzp BvlP4/+hZ9hoT5/r3G/VwRoAMFdqWArTpOBgk8PASow== DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d= messagingengine.com; h=cc: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=fm3; bh=AJY6sl B3E5b7La1Cr310C+dTZNsfWp+yQ4nl3p7aaRU=; b=bQSXxJeqBkGt7r9vnVLqzm vvsjAulqUJzS4stdE6AFWqLfJrQ3S9Fg7xMjmFaZfkXiebiL3YIFTDe3zsWmD8wp BYn4cVNGw7wLBaTAH85xHkIYHHjxNRfYvYjKsIpJxemli5YPkTZoYuYzMYK6Mlub JI9Qofr8XeB5+Ss1KaXXe6yztSr8EGwwZEnBIMqFGctl7sCD2H0WRLN8t7o4z8Us qeWx6RXGvlI/S/bksv0vvgGHY57sjePZ8Rt6OCHdr5dkP7bdxx8GllM61Wg2/jtT 6ekEh9qlIZogFxmqCuCvV7DRTrjThqKwuZA+IBStI6QGft/pge2RJBUVxkW2UXqQ == X-ME-Sender: X-ME-Proxy-Cause: gggruggvucftvghtrhhoucdtuddrgeduuddrudeiiedggeelucetufdoteggodetrfdotf fvucfrrhhofhhilhgvmecuhfgrshhtofgrihhlpdfqfgfvpdfurfetoffkrfgpnffqhgen uceurghilhhouhhtmecufedttdenucesvcftvggtihhpihgvnhhtshculddquddttddmne gfrhhlucfvnfffucdljedtmdenucfjughrpeffhffvuffkfhggtggujgesghdtreertddt vdenucfhrhhomhepofhitghhrggvlhcurfgrqhhuihgvrhcuoehmihgthhgrvghlsehprg hquhhivghrrdighiiiqeenucfkphepudduuddruddtvddrudektddrudekheenucfrrghr rghmpehmrghilhhfrhhomhepmhhitghhrggvlhesphgrqhhuihgvrhdrgiihiienucevlh hushhtvghrufhiiigvpedt X-ME-Proxy: Received: from paquier.xyz (ee0822lan1.rev.em-net.ne.jp [111.102.180.185]) by mail.messagingengine.com (Postfix) with ESMTPA id BFB6580063; Sun, 16 Jun 2019 22:01:20 -0400 (EDT) Date: Mon, 17 Jun 2019 11:01:07 +0900 From: Michael Paquier To: Fabio Pardi Cc: pgsql-performance@lists.postgresql.org Subject: Re: wal_log_hints benchmarks Message-ID: <20190617020107.GF3153@paquier.xyz> References: <43552731-a0ba-e9f5-838a-e1553d8ee705@portavita.eu> MIME-Version: 1.0 Content-Type: multipart/signed; micalg=pgp-sha512; protocol="application/pgp-signature"; boundary="9/eUdp+dLtKXvemk" Content-Disposition: inline In-Reply-To: <43552731-a0ba-e9f5-838a-e1553d8ee705@portavita.eu> List-Id: List-Help: List-Subscribe: List-Post: List-Owner: List-Archive: Precedence: bulk --9/eUdp+dLtKXvemk Content-Type: text/plain; charset=us-ascii Content-Disposition: inline On Fri, Jun 14, 2019 at 03:46:30PM +0200, Fabio Pardi wrote: > Maybe of some interest for the past, present and future community, I > benchmarked the impact of wal_log_hints with and without wal_compression > enabled. pgbench data is rather compressible per the format of its attributes, hence I am ready to bet that the compressibility would much much less if you use random text data for example. The amount of WAL generated also depends on the time it takes to run a transactions, and on the checkpoint timing, so I think that would you get better results by using a fixed number of transactions if you use pgbench, but that won't compare as much as a given workload in one session so as you can make sure that the same amount of WAL and full pages get generated. -- Michael --9/eUdp+dLtKXvemk Content-Type: application/pgp-signature; name="signature.asc" -----BEGIN PGP SIGNATURE----- iQIzBAABCgAdFiEEG72nH6vTowiyblFKnvQgOdbyQH0FAl0G9GMACgkQnvQgOdby QH1w4g//TzwEY0ClcZst8+uVGsyBzmwq/zpuC6i4ua5VVlGVhnGmGPJPedzPh1eH cWDefEhjqYctAbmLCVFjKhrM8jX3BUJjrOcVuopyVfT6jA15dl6JJkbybPARAQST CLk4TVMp4wC7K1TVTXpoGL4oAuS/1XG/4yFeINltntaI9TCyuxK5mwYqYKKiJ2Ug oCYCqw/bN3cirjAx6cHo3wVSffwDl2Yauw8g9Je2EM4fDSk5XC09YaWuprgeqI4e pa2kx6n+3t0BWwkO8he+Cs1R4++BG5marpnlc/vYLrlQ1N5aVxfbJ4dmyUn47reH sCEobBKUyoqUJd3G8GpR8L5DEDPlDBZAGMC2vLCITkN92lZB429zdVnW61H4GT8b cFwd7bOU0AfN5/i9Vy+VNNXwP7f+LC+OSlErFgHpH97B0fWZKEZHeQx4+gP5X61/ BuXjbS9DMrFclPVyqImMPQ97P2rDoQqt3ERji2q0XNEg5zA5f6JzzjLfgz0T+Qwm Reu7DVpb1sKy/26pB6rw6iK9OhCScZwg/TzjsJVtQbed48J38boY7bd/tuLrb5AN xcaXPAh0piYMIp8SOQ7aszIbz3Cz1JotWuveBKZZmKdC6D5M/24nvL42S3447V9N a88wv2vI2KURUdj1E7QwWlERItbdSjl2XfaofD6d0LcYqSFK7Sw= =6X92 -----END PGP SIGNATURE----- --9/eUdp+dLtKXvemk--