From mboxrd@z Thu Jan 1 00:00:00 1970 From: Thomas Rast Subject: Re: [GSoC] Designing a faster index format - Progress report week 13 Date: Wed, 25 Jul 2012 08:44:10 +0200 Message-ID: <87mx2omjb9.fsf@thomas.inf.ethz.ch> References: <20120716203300.GA1849@tgummerer.surfnet.iacbox> <7vwr23zb65.fsf@alter.siamese.dyndns.org> <20120717082452.GC1849@tgummerer.surfnet.iacbox> <500C1AA9.4000306@dewire.com> <7vfw8jsk5o.fsf@alter.siamese.dyndns.org> <87629fvaxz.fsf@thomas.inf.ethz.ch> <7vr4s3pkqr.fsf@alter.siamese.dyndns.org> <500DD05D.8030708@dewire.com> <87d33lqsrp.fsf@thomas.inf.ethz.ch> <7vy5m9f65b.fsf@alter.siamese.dyndns.org> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Cc: Robin Rosenberg , Thomas Gummerer , , , , JGit Developers list To: Junio C Hamano X-From: git-owner@vger.kernel.org Wed Jul 25 08:44:19 2012 Return-path: Envelope-to: gcvg-git-2@plane.gmane.org Received: from vger.kernel.org ([209.132.180.67]) by plane.gmane.org with esmtp (Exim 4.69) (envelope-from ) id 1StvKU-0008OC-OQ for gcvg-git-2@plane.gmane.org; Wed, 25 Jul 2012 08:44:19 +0200 Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753272Ab2GYGoN (ORCPT ); Wed, 25 Jul 2012 02:44:13 -0400 Received: from edge20.ethz.ch ([82.130.99.26]:7719 "EHLO edge20.ethz.ch" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752591Ab2GYGoM (ORCPT ); Wed, 25 Jul 2012 02:44:12 -0400 Received: from CAS12.d.ethz.ch (172.31.38.212) by edge20.ethz.ch (82.130.99.26) with Microsoft SMTP Server (TLS) id 14.2.298.4; Wed, 25 Jul 2012 08:44:11 +0200 Received: from thomas.inf.ethz.ch.ethz.ch (129.132.153.233) by CAS12.d.ethz.ch (172.31.38.212) with Microsoft SMTP Server (TLS) id 14.2.298.4; Wed, 25 Jul 2012 08:44:10 +0200 In-Reply-To: <7vy5m9f65b.fsf@alter.siamese.dyndns.org> (Junio C. Hamano's message of "Tue, 24 Jul 2012 09:58:08 -0700") User-Agent: Gnus/5.13 (Gnus v5.13) Emacs/23.3 (gnu/linux) X-Originating-IP: [129.132.153.233] Sender: git-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: git@vger.kernel.org Archived-At: Junio C Hamano writes: > Thomas Rast writes: > >> Junio's index-v4 was a speed boost mainly because it cuts down on the >> size of the index. Do we want to throw that out? > > That's pretty much orthogonal, isn't it? > > The index-v4 is merely to show how a stupid prefix compression of > pathnames without nothing else would reduce the file size and I/O > cost, in order to set the bar for anything more clever than that. > > I thought that this discussion is about keeping, squishing, or > discarding part of the cached stat info, and nobody is suggesting > what to do with the prefix compression of pathnames. True, sorry for being so confusing. 'Throw "that" out' was meant to refer to the observation that smaller indexes are generally faster. Whether this matters in the long run is another question. Perhaps partial loading combined with something like inotify can avoid full reads in most operations. -- Thomas Rast trast@{inf,student}.ethz.ch