From 52fe4aeb3d59502700ee8a1f679a5ee76b7ccaa1 Mon Sep 17 00:00:00 2001 From: Tomi Ollila Date: Fri, 30 Nov 2012 09:31:31 +0200 Subject: [PATCH] Re: On disk tag storage format --- 67/1dacb3124b4b86f1f5ed559e9550c1155faf93 | 84 +++++++++++++++++++++++ 1 file changed, 84 insertions(+) create mode 100644 67/1dacb3124b4b86f1f5ed559e9550c1155faf93 diff --git a/67/1dacb3124b4b86f1f5ed559e9550c1155faf93 b/67/1dacb3124b4b86f1f5ed559e9550c1155faf93 new file mode 100644 index 000000000..483e4e91c --- /dev/null +++ b/67/1dacb3124b4b86f1f5ed559e9550c1155faf93 @@ -0,0 +1,84 @@ +Return-Path: +X-Original-To: notmuch@notmuchmail.org +Delivered-To: notmuch@notmuchmail.org +Received: from localhost (localhost [127.0.0.1]) + by olra.theworths.org (Postfix) with ESMTP id 983B4431FBC + for ; Thu, 29 Nov 2012 23:31:38 -0800 (PST) +X-Virus-Scanned: Debian amavisd-new at olra.theworths.org +X-Spam-Flag: NO +X-Spam-Score: 0 +X-Spam-Level: +X-Spam-Status: No, score=0 tagged_above=-999 required=5 tests=[none] + autolearn=disabled +Received: from olra.theworths.org ([127.0.0.1]) + by localhost (olra.theworths.org [127.0.0.1]) (amavisd-new, port 10024) + with ESMTP id LJ4X4bczkd4O for ; + Thu, 29 Nov 2012 23:31:34 -0800 (PST) +Received: from guru.guru-group.fi (guru.guru-group.fi [46.183.73.34]) + by olra.theworths.org (Postfix) with ESMTP id D99F1431FAF + for ; Thu, 29 Nov 2012 23:31:33 -0800 (PST) +Received: from guru.guru-group.fi (localhost [IPv6:::1]) + by guru.guru-group.fi (Postfix) with ESMTP id 6E1D91000E5; + Fri, 30 Nov 2012 09:31:31 +0200 (EET) +From: Tomi Ollila +To: Eirik Byrkjeflot Anonsen , + notmuch mailing list +Subject: Re: On disk tag storage format +In-Reply-To: <874nk8td7p.fsf@star.eba> +References: <874nk8v9zw.fsf@zancas.localnet> <874nk8td7p.fsf@star.eba> +User-Agent: Notmuch/0.14+116~g29fcdb5 (http://notmuchmail.org) Emacs/24.2.1 + (x86_64-unknown-linux-gnu) +X-Face: HhBM'cA~ +MIME-Version: 1.0 +Content-Type: text/plain +X-BeenThere: notmuch@notmuchmail.org +X-Mailman-Version: 2.1.13 +Precedence: list +List-Id: "Use and development of the notmuch mail system." + +List-Unsubscribe: , + +List-Archive: +List-Post: +List-Help: +List-Subscribe: , + +X-List-Received-Date: Fri, 30 Nov 2012 07:31:38 -0000 + +On Thu, Nov 29 2012, Eirik Byrkjeflot Anonsen wrote: + +> David Bremner writes: +> +>> Austin outlined on IRC a way of representing tags on disk as hardlinks +>> to messages. In order to make the discussion more concrete, I wrote a +>> prototype in python to dump the notmuch database to this format. On my +>> 250k messages, this creates 40k new hardlinks, and uses about 5M of +>> diskspace. The dump process takes about 20s on +>> my core i7 machine. With symbolic links, the same database takes about +>> 150M of disk space; this isn't great but it isn't unbearable either. +> +> And eating 40k inodes, I suppose. Which may matter to some systems. +> (Hardlinks do not use extra inodes, as they are just directory entries +> pointing to already existing inodes). +> +> Of course, the space usage also depends on the file system, as e.g. ext2 +> would use 1 complete block (typically 4kiB) to store the file name +> pointed to per symlink. ReiserFS would probably use 5M for the +> directory entries and another 5M for the symlink data (wild guess). + +IIRC in mid 1990's (some) frisbee fs stored many symbolic links to one +inode and, at the same time, stored multiple link names to same fs block +... note that IIRC :D + +> eirik + +Tomi + +> _______________________________________________ +> notmuch mailing list +> notmuch@notmuchmail.org +> http://notmuchmail.org/mailman/listinfo/notmuch -- 2.26.2