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 8D1EE651D for ; Tue, 19 Jul 2011 03:07:07 +0000 (UTC) Received: (qmail 33328 invoked by uid 500); 19 Jul 2011 03:07:05 -0000 Delivered-To: apmail-cassandra-user-archive@cassandra.apache.org Received: (qmail 32896 invoked by uid 500); 19 Jul 2011 03:06:47 -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 32887 invoked by uid 99); 19 Jul 2011 03:06:43 -0000 Received: from nike.apache.org (HELO nike.apache.org) (192.87.106.230) by apache.org (qpsmtpd/0.29) with ESMTP; Tue, 19 Jul 2011 03:06:43 +0000 X-ASF-Spam-Status: No, hits=-0.7 required=5.0 tests=FREEMAIL_FROM,RCVD_IN_DNSWL_LOW,SPF_PASS,T_TO_NO_BRKTS_FREEMAIL X-Spam-Check-By: apache.org Received-SPF: pass (nike.apache.org: domain of jbellis@gmail.com designates 74.125.82.172 as permitted sender) Received: from [74.125.82.172] (HELO mail-wy0-f172.google.com) (74.125.82.172) by apache.org (qpsmtpd/0.29) with ESMTP; Tue, 19 Jul 2011 03:06:36 +0000 Received: by wyj26 with SMTP id 26so1787604wyj.31 for ; Mon, 18 Jul 2011 20:06:16 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=gamma; h=mime-version:in-reply-to:references:from:date:message-id:subject:to :content-type; bh=BR1fhv8OFXj2dkTGSAierXsihJmxb9IC0tCtw0JuT7o=; b=r4l7I6WiLwz4TNxXRECO1dvpZYi+b+lw8PVw+FoVBLn7olD2Bj7LvdxQN1d+rJT6Sa Wm50VZlVUj/IeieRxmago5lNMiPaPUSuba4MhV+p9+3CRAuJTyh0pvPq0Rk2eeGBYbCb UrhAx3BcKxZvOmA2yh2HGI+sikfJvU/6dE0zQ= Received: by 10.216.30.9 with SMTP id j9mr5742775wea.82.1311044775131; Mon, 18 Jul 2011 20:06:15 -0700 (PDT) MIME-Version: 1.0 Received: by 10.216.52.132 with HTTP; Mon, 18 Jul 2011 20:05:55 -0700 (PDT) In-Reply-To: References: From: Jonathan Ellis Date: Mon, 18 Jul 2011 22:05:55 -0500 Message-ID: Subject: Re: How to keep only exactly column of key To: user@cassandra.apache.org Content-Type: text/plain; charset=ISO-8859-1 X-Virus-Checked: Checked by ClamAV on apache.org You can use expiring columns to say "only the last N seconds' of data." But not counts per se for the reasons Aaron gave. On Mon, Jul 18, 2011 at 10:22 AM, JKnight JKnight wrote: > Dear all, > I want to keep only 100 column of a key: when I add a column for a key, if > the number column of key is 100, another column (by order) will be deleted. > Does Cassandra have setting for that? > > -- > Best regards, > JKnight > -- Jonathan Ellis Project Chair, Apache Cassandra co-founder of DataStax, the source for professional Cassandra support http://www.datastax.com