From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from localhost (localhost [127.0.0.1]) by arlo.cworth.org (Postfix) with ESMTP id 3D3C56DE099D for ; Mon, 10 Aug 2015 02:40:31 -0700 (PDT) X-Virus-Scanned: Debian amavisd-new at cworth.org X-Spam-Flag: NO X-Spam-Score: -0.11 X-Spam-Level: X-Spam-Status: No, score=-0.11 tagged_above=-999 required=5 tests=[AWL=0.097, DKIM_SIGNED=0.1, DKIM_VALID=-0.1, DKIM_VALID_AU=-0.1, RCVD_IN_DNSWL_LOW=-0.7, RCVD_IN_MSPIKE_H3=-0.01, RCVD_IN_MSPIKE_WL=-0.01, RCVD_IN_SORBS_WEB=0.614, SPF_PASS=-0.001] autolearn=disabled Received: from arlo.cworth.org ([127.0.0.1]) by localhost (arlo.cworth.org [127.0.0.1]) (amavisd-new, port 10024) with ESMTP id 9puF84tGk56y for ; Mon, 10 Aug 2015 02:40:29 -0700 (PDT) Received: from mail-wi0-f177.google.com (mail-wi0-f177.google.com [209.85.212.177]) by arlo.cworth.org (Postfix) with ESMTPS id F07C36DE0244 for ; Mon, 10 Aug 2015 02:40:28 -0700 (PDT) Received: by wijp15 with SMTP id p15so128138393wij.0 for ; Mon, 10 Aug 2015 02:40:26 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=schoepe.org; s=google; h=from:to:subject:in-reply-to:references:user-agent:date:message-id :mime-version:content-type; bh=NM5vOvefEmGvwLmbUPmyv4Lt4vIzRMETzJBnV9Ep0kY=; b=NMerkH3ZruGDymV75CUqw4AtKTDxqvv8x1NEXz0VoUB/R6Cw7Y7OB1p6o8Fjqu2u4H FYq/ykeoA+cBGUklYyakWvsbJ3CITAYm+asJg7ziAVLWBzRnYlfQWEVqUgSXSeiXy6bP bFlhVjkvXc8jYIajpTMWOAE1F/JhcrmawC3QE= X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20130820; h=x-gm-message-state:from:to:subject:in-reply-to:references :user-agent:date:message-id:mime-version:content-type; bh=NM5vOvefEmGvwLmbUPmyv4Lt4vIzRMETzJBnV9Ep0kY=; b=cLEk5UbBfYnJPHRoe7uewu9W2ap03Fvyz73HuCaCMAJdKnmeY4nGPAs7QYj81g6OVZ M2+dWuaeJcAihSO1//qR1D7HmaZwkpA0vnxW3zhuP00pdkwuXrzmG6FblgeLds+7+WSy dkNvre1vMeo5hlOMJyrGC2hoWH6GYWWuDbmudWF7W/rGgD3t5O/dV6bmawsbD84XZpX7 MXhyFe/b9evLBMD7EqIedCuUMyBczSCf4WWuj6Lw7r3bAumFeSk9WAEJEFeMdWeoTyRo HfPUGxrNImsGazCMyCXy/hjfYBKWsh+hgg8U2C7ZweGZ3BdIdJ9l34v5Zk4AqERsB/X5 1njw== X-Gm-Message-State: ALoCoQlpHEhqeV3uUrvJep6/MvbEHfKSrAFvuAz9/UFxyXXg9wSiuAqQB/gki4UDHsX+TnjF9jbv X-Received: by 10.194.172.130 with SMTP id bc2mr46488639wjc.85.1439199626796; Mon, 10 Aug 2015 02:40:26 -0700 (PDT) Received: from localhost (ip-80-226-24-8.vodafone-net.de. [80.226.24.8]) by smtp.gmail.com with ESMTPSA id fs8sm1649964wib.0.2015.08.10.02.40.24 (version=TLSv1.2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128/128); Mon, 10 Aug 2015 02:40:25 -0700 (PDT) From: Daniel Schoepe To: David Bremner , notmuch@notmuchmail.org Subject: Re: [PATCH 4/5] cli: add global option "--uuid" In-Reply-To: <1439112285-6681-5-git-send-email-david@tethera.net> References: <1439112285-6681-1-git-send-email-david@tethera.net> <1439112285-6681-5-git-send-email-david@tethera.net> User-Agent: Notmuch/0.20.2+58~g20ed908 (http://notmuchmail.org) Emacs/24.5.1 (x86_64-unknown-linux-gnu) Date: Mon, 10 Aug 2015 11:40:21 +0200 Message-ID: <87fv3rtray.fsf@schoepe.localhost> MIME-Version: 1.0 Content-Type: text/plain X-BeenThere: notmuch@notmuchmail.org X-Mailman-Version: 2.1.18 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: Mon, 10 Aug 2015 09:40:31 -0000 On Sun, 09 Aug 2015 11:24+0200, David Bremner wrote: > + ``--uuid=HEX`` > + Enforce that the database UUID (a unique identifier which > + persists until e.g. the database is compacted) > + is HEX; exit with an error if it is not. This is useful to > + detect rollover in modification counts on messages. You can > + find this UUID in the first column of output from > + ``notmuch count --output=modifications`` I think it's not entirely clear what the connection between the UUID and the revisions on messages is. For example, compacting a database shouldn't make a difference "extensionally", so the naive assumption might be that the UUID, or, maybe more importantly, the revision counts don't change. For example, if lastmod queries are used to incrementally back up or synchronize tags, then it doesn't matter if the database got compacted, all one cares about are the changes to messages' tags since an earlier point. Based on quick experiments, it seems that the revisions don't change when compacting the database; is this something that the patches guarantee or a coincidence? Best regards, Daniel