From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from localhost (localhost [127.0.0.1]) by olra.theworths.org (Postfix) with ESMTP id CADCD431FBC for ; Wed, 17 Feb 2010 16:39:08 -0800 (PST) X-Virus-Scanned: Debian amavisd-new at olra.theworths.org X-Spam-Flag: NO X-Spam-Score: -1.236 X-Spam-Level: X-Spam-Status: No, score=-1.236 tagged_above=-999 required=5 tests=[AWL=-0.496, BAYES_20=-0.74] autolearn=ham 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 7qsG0iKT+B8a for ; Wed, 17 Feb 2010 16:39:08 -0800 (PST) Received: from mail-vw0-f53.google.com (mail-vw0-f53.google.com [209.85.212.53]) by olra.theworths.org (Postfix) with ESMTP id DA413431FAE for ; Wed, 17 Feb 2010 16:39:07 -0800 (PST) Received: by vws16 with SMTP id 16so668382vws.26 for ; Wed, 17 Feb 2010 16:39:07 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=gamma; h=domainkey-signature:received:received:content-type:subject:from:to :in-reply-to:references:date:message-id:user-agent :content-transfer-encoding; bh=Q+m598pueSVYA0NKetS20hfcY0xA5PeBlX5TOZmjCTY=; b=WX/cnNEtnHnH23SiUUq7P/onNduZLegoJYgajzgv4//0Dgzo92sX0ihaPKRdbAbOoo tRA49+amDKwcSf6d2JGsKQ6sjQ2D9kgkAUyhHeK7e3cXdIIpNWerb1H6wZWxxmghvWm8 BVb4vudWz7xYBLc6ScrKzVEcxB6BizwY0Pn5M= DomainKey-Signature: a=rsa-sha1; c=nofws; d=gmail.com; s=gamma; h=content-type:subject:from:to:in-reply-to:references:date:message-id :user-agent:content-transfer-encoding; b=cbaww3gXHBwGYkzhblXOyZxK3TFUZPSm1euMCgqCktHNUAE0QVVZ3xm8TJXKcVAuIw gx0lWLXU0kfTwxB/ip8qNKycuHnUMSewVylEFUvq8in4yVSIMSpcEi6LI8bbG3SiTvjf MlprhEhokUEZpEfJaG0NF7ho6eRBtsmJU8sqc= Received: by 10.220.122.7 with SMTP id j7mr2425962vcr.54.1266453547143; Wed, 17 Feb 2010 16:39:07 -0800 (PST) Received: from localhost (umass-959-129.wireless.umass.edu [128.119.77.129]) by mx.google.com with ESMTPS id 25sm13838047vws.21.2010.02.17.16.39.05 (version=TLSv1/SSLv3 cipher=RC4-MD5); Wed, 17 Feb 2010 16:39:05 -0800 (PST) Content-Type: text/plain; charset=UTF-8 From: Ben Gamari To: notmuch In-reply-to: <20100217235211.GC2628@lapse.rw.madduck.net> References: <20100215002914.GA22402@flamingspork.com> <20100217012101.GD8249@lapse.rw.madduck.net> <1266418124-sup-6308@ben-laptop> <3wd3a0z7jjv.fsf@mhdcelk-nx01.amd.com> <1266435265-sup-5024@ben-laptop> <20100217235211.GC2628@lapse.rw.madduck.net> Date: Wed, 17 Feb 2010 19:39:03 -0500 Message-Id: <1266453115-sup-7880@ben-laptop> User-Agent: Sup/git Content-Transfer-Encoding: 8bit Subject: Re: Mail in git 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: Thu, 18 Feb 2010 00:39:09 -0000 Excerpts from martin f krafft's message of Wed Feb 17 18:52:11 -0500 2010: > also sprach Ben Gamari [2010.02.18.0834 +1300]: > > Excerpts from Mark Anderson's message of Wed Feb 17 14:23:48 -0500 > > 2010: > > > But if we have notmuch as a cache of the tags, then don't we > > > already know the tree objects that need updating? Yes, we would > > > probably need some consistency checks for when things don't work > > > as planned, but in the common case we ought to always know. > > > > > Cached or not, rewriting would still be an incredibly (e.g. > > prohibitively or close to it) expensive operation for a large > > mailstore. > > Why? Well, would involve creating n objects and unlinking n objects > for n tags, but it would be constant in the number of messages, no? Yes, it would be linear in number of tags. I suppose if messages weren't stored in the top-level tree nodes, then it would still be linear, although with a slope equal to the reciprocal of the fan-out. This has the potential to be very reasonable performance-wise. - Ben