From mboxrd@z Thu Jan 1 00:00:00 1970 From: Stephen Frost Subject: Re: Improve lseek scalability v3 Date: Mon, 19 Sep 2011 08:31:00 -0400 Message-ID: <20110919123100.GJ12765@tamriel.snowman.net> References: <1316128013-21980-1-git-send-email-andi@firstfloor.org> <201109161616.50004.andres@anarazel.de> <20110916153620.GA9913@parisc-linux.org> <201109161927.34472.andres@anarazel.de> <20110916200817.GD28519@kvack.org> Mime-Version: 1.0 Content-Type: multipart/signed; micalg=pgp-sha1; protocol="application/pgp-signature"; boundary="GmIAiBEz2jSsbeLA" Cc: Andres Freund , Matthew Wilcox , Andi Kleen , viro@zeniv.linux.org.uk, linux-fsdevel@vger.kernel.org, linux-kernel@vger.kernel.org, robertmhaas@gmail.com, pgsql-hackers@postgresql.org To: Benjamin LaHaise Return-path: Content-Disposition: inline In-Reply-To: <20110916200817.GD28519@kvack.org> List-Archive: List-Help: List-Owner: List-Post: List-Subscribe: List-Unsubscribe: Sender: pgsql-hackers-owner@postgresql.org List-Id: linux-fsdevel.vger.kernel.org --GmIAiBEz2jSsbeLA Content-Type: text/plain; charset=us-ascii Content-Disposition: inline Content-Transfer-Encoding: quoted-printable * Benjamin LaHaise (bcrl@kvack.org) wrote: > For such tables, can't Postgres track the size of the file internally? I= 'm=20 > assuming it's keeping file descriptors open on the tables it manages, in= =20 > which case when it writes to a file to extend it, the internally stored s= ize=20 > could be updated. Not making a syscall at all would scale far better tha= n=20 > even a modified lseek() will perform. We'd have to have it in shared memory and have a lock around it, it wouldn't be cheap at all. Thanks, =09 Stephen --GmIAiBEz2jSsbeLA Content-Type: application/pgp-signature; name="signature.asc" Content-Description: Digital signature Content-Disposition: inline -----BEGIN PGP SIGNATURE----- Version: GnuPG v1.4.10 (GNU/Linux) iEYEARECAAYFAk53NgQACgkQrzgMPqB3kigQkACbBedEBkNbhU0Eg/LgMO7xPcdZ VRgAn20rNS0pVWDTsFdladAr9UzPxo8Z =K4cW -----END PGP SIGNATURE----- --GmIAiBEz2jSsbeLA--