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 3941A95B0 for ; Wed, 5 Oct 2011 18:16:13 +0000 (UTC) Received: (qmail 33099 invoked by uid 500); 5 Oct 2011 18:16:11 -0000 Delivered-To: apmail-cassandra-user-archive@cassandra.apache.org Received: (qmail 33068 invoked by uid 500); 5 Oct 2011 18:16:11 -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 33060 invoked by uid 99); 5 Oct 2011 18:16:11 -0000 Received: from nike.apache.org (HELO nike.apache.org) (192.87.106.230) by apache.org (qpsmtpd/0.29) with ESMTP; Wed, 05 Oct 2011 18:16:11 +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 209.85.215.172 as permitted sender) Received: from [209.85.215.172] (HELO mail-ey0-f172.google.com) (209.85.215.172) by apache.org (qpsmtpd/0.29) with ESMTP; Wed, 05 Oct 2011 18:16:05 +0000 Received: by eye22 with SMTP id 22so697939eye.31 for ; Wed, 05 Oct 2011 11:15:45 -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:content-transfer-encoding; bh=JH6SXdZB4ayZLQ8/D2yaNSKKJgMW8d0aBtETf6qmgp0=; b=G63joYkDcOaQ4SjPWtMHnXVTuyq9YaVzQjzQfrgbznP+73Qm03BBv1y8xgUt5bxDDW br4f/3sYGJiOIbvN0Dz3bVRxTZYyCM9Rqt/4+JeRCJg7EZDKlVGfdUoItnN0uq68OuMc o+oobgWjdlncbWoPtZSN5LyW1XA++7uD6KOWk= Received: by 10.213.112.204 with SMTP id x12mr1297880ebp.14.1317838545156; Wed, 05 Oct 2011 11:15:45 -0700 (PDT) MIME-Version: 1.0 Received: by 10.213.14.4 with HTTP; Wed, 5 Oct 2011 11:15:25 -0700 (PDT) In-Reply-To: <4E8C9D60.7000109@likewise.com> References: <4E8C9D60.7000109@likewise.com> From: Jonathan Ellis Date: Wed, 5 Oct 2011 13:15:25 -0500 Message-ID: Subject: Re: Question about sharding of rows and atomicity To: user@cassandra.apache.org Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: quoted-printable X-Virus-Checked: Checked by ClamAV on apache.org On Wed, Oct 5, 2011 at 1:09 PM, Don Smith wrote: > Does Cassandra shard the columns of a single row across multiple nodes so > that to read the columns of the row it may need access to multiple nodes? > I'd say "no." Correct. > =A0 Will a read from a given node ever return partial results or > is the write to a node of a row atomic? http://wiki.apache.org/cassandra/FAQ#batch_mutate_atomic --=20 Jonathan Ellis Project Chair, Apache Cassandra co-founder of DataStax, the source for professional Cassandra support http://www.datastax.com