Mailing-List: contact cassandra-user-help@incubator.apache.org; run by ezmlm
Precedence: bulk
Reply-To: cassandra-user@incubator.apache.org
Received-SPF: pass (athena.apache.org: domain of jbellis@gmail.com designates
 209.85.219.212 as permitted sender)
DomainKey-Signature: a=rsa-sha1; c=nofws;
        d=gmail.com; s=gamma;
        h=mime-version:in-reply-to:references:from:date:message-id:subject:to
         :content-type;
        b=SdZvSbd6DRN6lBfv1fXVsUpP8ys7/FCBNJoVlLuB31DVF9y3VojIc3i/kMSGu1CnFB
         0iJsPaTZFa24Q2fOBMOos1w47OmxCXnASYtRSEFWJ37+j6tHF2haHor245BsUgvxTv6M
         ErgiA7kcskc9zRd4mLjfITYlvJP7q/sATItHI=
MIME-Version: 1.0
In-Reply-To: <ac68ab851001121239u12c549xb3d8acffc04239dc@mail.gmail.com>
References: <ac68ab851001120845j52a61863vde7b3392f1de62cb@mail.gmail.com>
	<e06563881001120856v6837528ak5082b767fcd68bb3@mail.gmail.com>
	<ac68ab851001121239u12c549xb3d8acffc04239dc@mail.gmail.com>
From: Jonathan Ellis <jbellis@gmail.com>
Date: Tue, 12 Jan 2010 15:29:57 -0600
Message-ID: <e06563881001121329t2f13473et52855b5fc03b4ab8@mail.gmail.com>
Subject: Re: Cassandra and TTL
To: cassandra-user@incubator.apache.org
Content-Type: text/plain; charset=ISO-8859-1

On Tue, Jan 12, 2010 at 2:39 PM, Sylvain Lebresne <sylvain@yakaz.com> wrote:
>> If truncating old sstables entirely
>> (https://issues.apache.org/jira/browse/CASSANDRA-531) meets your
>> needs, that is going to be less work and more performant.
>
> Well, I'm not sure I understand completely this ticket. The part in the
> comment saying "drop all sstables older than X" seems to be something helpful.
> But aren't sstables regularly merged together, thus mixing "older" data with
> newer data ?

Right, that is why the ticket says you would want to disable
compaction if you want to truncate less than the whole CF.

> That is, is this 'truncate with a timestamp t' always remove *all* columns
> with a timestamp older than t ?

Yes.

-Jonathan