Return-Path: Delivered-To: apmail-cassandra-user-archive@www.apache.org Received: (qmail 17312 invoked from network); 1 Dec 2010 17:37:15 -0000 Received: from unknown (HELO mail.apache.org) (140.211.11.3) by 140.211.11.9 with SMTP; 1 Dec 2010 17:37:15 -0000 Received: (qmail 47922 invoked by uid 500); 1 Dec 2010 17:37:13 -0000 Delivered-To: apmail-cassandra-user-archive@cassandra.apache.org Received: (qmail 47889 invoked by uid 500); 1 Dec 2010 17:37:13 -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 47881 invoked by uid 99); 1 Dec 2010 17:37:13 -0000 Received: from nike.apache.org (HELO nike.apache.org) (192.87.106.230) by apache.org (qpsmtpd/0.29) with ESMTP; Wed, 01 Dec 2010 17:37:13 +0000 X-ASF-Spam-Status: No, hits=-0.7 required=10.0 tests=RCVD_IN_DNSWL_LOW,SPF_PASS X-Spam-Check-By: apache.org Received-SPF: pass (nike.apache.org: domain of rcoli@digg.com designates 209.85.214.44 as permitted sender) Received: from [209.85.214.44] (HELO mail-bw0-f44.google.com) (209.85.214.44) by apache.org (qpsmtpd/0.29) with ESMTP; Wed, 01 Dec 2010 17:37:04 +0000 Received: by bwz12 with SMTP id 12so6973379bwz.31 for ; Wed, 01 Dec 2010 09:36:43 -0800 (PST) Received: by 10.204.62.132 with SMTP id x4mr3345152bkh.15.1291225003599; Wed, 01 Dec 2010 09:36:43 -0800 (PST) Received: from rcolis-MacBook-Pro.local (c-98-210-205-15.hsd1.ca.comcast.net [98.210.205.15]) by mx.google.com with ESMTPS id d27sm3544329bkw.14.2010.12.01.09.36.41 (version=SSLv3 cipher=RC4-MD5); Wed, 01 Dec 2010 09:36:42 -0800 (PST) Message-ID: <4CF687A4.1010407@digg.com> Date: Wed, 01 Dec 2010 09:36:36 -0800 From: Robert Coli User-Agent: Mozilla/5.0 (Macintosh; U; Intel Mac OS X 10.6; en-US; rv:1.9.2.12) Gecko/20101027 Thunderbird/3.1.6 MIME-Version: 1.0 To: user@cassandra.apache.org Subject: Re: Is there any way to store muti-version data based on the timestamp? References: In-Reply-To: Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 7bit X-Virus-Checked: Checked by ClamAV on apache.org On 12/1/10 4:56 AM, Daniel Lundin wrote: >> Correct. Unlike BigTable and HBase, Cassandra columns don't have a >> version dimension. >> Timestamp is used for (crude) conflict resolution, and older versions >> are always overwritten. I would be careful with the word "overwritten" here as it obfuscated the immutability of SSTables, and conceptual understanding of same is important to understanding the actual versioning behavior and how it relates to what data has to be read to satisfy queries. :) =Rob