Return-Path: Delivered-To: apmail-cassandra-user-archive@www.apache.org Received: (qmail 94803 invoked from network); 21 Jun 2010 09:26:39 -0000 Received: from unknown (HELO mail.apache.org) (140.211.11.3) by 140.211.11.9 with SMTP; 21 Jun 2010 09:26:39 -0000 Received: (qmail 1336 invoked by uid 500); 21 Jun 2010 09:26:38 -0000 Delivered-To: apmail-cassandra-user-archive@cassandra.apache.org Received: (qmail 1118 invoked by uid 500); 21 Jun 2010 09:26:35 -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 1109 invoked by uid 99); 21 Jun 2010 09:26:34 -0000 Received: from nike.apache.org (HELO nike.apache.org) (192.87.106.230) by apache.org (qpsmtpd/0.29) with ESMTP; Mon, 21 Jun 2010 09:26:34 +0000 X-ASF-Spam-Status: No, hits=-0.0 required=10.0 tests=RCVD_IN_DNSWL_NONE,SPF_PASS X-Spam-Check-By: apache.org Received-SPF: pass (nike.apache.org: local policy) Received: from [208.113.200.5] (HELO blingymail-a1.g.dreamhost.com) (208.113.200.5) by apache.org (qpsmtpd/0.29) with ESMTP; Mon, 21 Jun 2010 09:26:24 +0000 Received: from [10.0.1.153] (121-73-157-230.cable.telstraclear.net [121.73.157.230]) (using TLSv1 with cipher AES128-SHA (128/128 bits)) (No client certificate requested) by blingymail-a1.g.dreamhost.com (Postfix) with ESMTP id A66445CE76 for ; Mon, 21 Jun 2010 02:26:02 -0700 (PDT) Content-Type: text/plain; charset=us-ascii Mime-Version: 1.0 (Apple Message framework v1081) Subject: Re: Is there a penalty to a SuperColumn? From: aaron morton In-Reply-To: Date: Mon, 21 Jun 2010 21:26:00 +1200 Content-Transfer-Encoding: quoted-printable Message-Id: <0E3558CE-7994-41D4-B885-FE11E8C5E259@thelastpickle.com> References: To: user@cassandra.apache.org X-Mailer: Apple Mail (2.1081) X-Virus-Checked: Checked by ClamAV on apache.org The only one I know is the one listed in = http://wiki.apache.org/cassandra/CassandraLimitations The sub columns in a super column are not indexed, so the entire super = column must be read into memory when accessed.=20 I've tried using Super Columns and namespacing columns in a standard = column, e.g. columns called "foo.bar". But prefer using Super Columns = when representing one "entity" with different groups of columns.=20 Aaron On 21 Jun 2010, at 20:33, David Boxenhorn wrote: > I have a column family that doesn't need to be a supercolumn family = right now, but I think it *might* need to be one in the future. I'm = considering making it a supercolumn family with only one supercolumn per = row to give me flexibility going forward. >=20 > My question: Is there a penalty to this? If there is, I will make it a = regular column family and hope for the best.=20