Return-Path: X-Original-To: apmail-cassandra-user-archive@www.apache.org Delivered-To: apmail-cassandra-user-archive@www.apache.org Received: from mail.apache.org (hermes.apache.org [140.211.11.3]) by minotaur.apache.org (Postfix) with SMTP id 340F1421F for ; Wed, 13 Jul 2011 09:05:58 +0000 (UTC) Received: (qmail 60683 invoked by uid 500); 13 Jul 2011 09:05:55 -0000 Delivered-To: apmail-cassandra-user-archive@cassandra.apache.org Received: (qmail 60434 invoked by uid 500); 13 Jul 2011 09:05:41 -0000 Mailing-List: contact user-help@cassandra.apache.org; run by ezmlm Precedence: bulk List-Help: List-Unsubscribe: List-Post: List-Id: Reply-To: user@cassandra.apache.org Delivered-To: mailing list user@cassandra.apache.org Received: (qmail 60012 invoked by uid 99); 13 Jul 2011 09:05:38 -0000 Received: from athena.apache.org (HELO athena.apache.org) (140.211.11.136) by apache.org (qpsmtpd/0.29) with ESMTP; Wed, 13 Jul 2011 09:05:38 +0000 X-ASF-Spam-Status: No, hits=1.5 required=5.0 tests=FREEMAIL_FROM,HTML_MESSAGE,RCVD_IN_DNSWL_LOW,SPF_PASS,T_TO_NO_BRKTS_FREEMAIL X-Spam-Check-By: apache.org Received-SPF: pass (athena.apache.org: domain of yulinyen@gmail.com designates 209.85.161.43 as permitted sender) Received: from [209.85.161.43] (HELO mail-fx0-f43.google.com) (209.85.161.43) by apache.org (qpsmtpd/0.29) with ESMTP; Wed, 13 Jul 2011 09:05:32 +0000 Received: by fxg17 with SMTP id 17so4813692fxg.30 for ; Wed, 13 Jul 2011 02:05:11 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=gamma; h=mime-version:in-reply-to:references:date:message-id:subject:from:to :content-type; bh=fkUB10HrjnRUZKFJmJ+eMz58JQLDZucuMlzcVJ0s3jE=; b=e0sAmAPe8aGx+v4aOhnB4qMntk/taepsS+c9ENfFngZ7PObMWe31Mie8lldhJjY3Uw qmMbpGKt1Q8yW5YbgEmAlBSxgXlTGnNhC71gNTLoUq1N9AIzAFTSrbLG4Mb3TTntjrrv tM2Q+lBsAqpaQUnI9kk20Jp+ycqYfkinErrEE= MIME-Version: 1.0 Received: by 10.223.16.136 with SMTP id o8mr1422025faa.21.1310547911553; Wed, 13 Jul 2011 02:05:11 -0700 (PDT) Received: by 10.223.101.202 with HTTP; Wed, 13 Jul 2011 02:05:11 -0700 (PDT) In-Reply-To: References: Date: Wed, 13 Jul 2011 17:05:11 +0800 Message-ID: Subject: Re: Why do Digest Queries return hash instead of timestamp? From: Boris Yen To: user@cassandra.apache.org Content-Type: multipart/alternative; boundary=001517402910bab43604a7efb64e --001517402910bab43604a7efb64e Content-Type: text/plain; charset=ISO-8859-1 I guess it is because the timestamp does not guarantee data consistency, but hash does. Boris On Wed, Jul 13, 2011 at 4:27 PM, David Boxenhorn wrote: > I just saw this > > http://wiki.apache.org/cassandra/DigestQueries > > and I was wondering why it returns a hash of the data. Wouldn't it be > better and easier to return the timestamp? You don't really care what the > data is, you only care whether it is more or less recent than another piece > of data. > --001517402910bab43604a7efb64e Content-Type: text/html; charset=ISO-8859-1 Content-Transfer-Encoding: quoted-printable I guess it is because the timestamp does not guarantee data consistency, bu= t hash does.

Boris

On = Wed, Jul 13, 2011 at 4:27 PM, David Boxenhorn <david@citypath.com> wrote:
I just saw this

h= ttp://wiki.apache.org/cassandra/DigestQueries

and I was wondering why it returns a hash of the data. Wouldn't it = be better and easier to return the timestamp? You don't really care wha= t the data is, you only care whether it is more or less recent than another= piece of data.

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