Return-Path: Delivered-To: apmail-cassandra-user-archive@www.apache.org Received: (qmail 44331 invoked from network); 10 May 2010 18:06:53 -0000 Received: from unknown (HELO mail.apache.org) (140.211.11.3) by 140.211.11.9 with SMTP; 10 May 2010 18:06:53 -0000 Received: (qmail 10459 invoked by uid 500); 10 May 2010 18:06:52 -0000 Delivered-To: apmail-cassandra-user-archive@cassandra.apache.org Received: (qmail 10434 invoked by uid 500); 10 May 2010 18:06:52 -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 10426 invoked by uid 99); 10 May 2010 18:06:52 -0000 Received: from nike.apache.org (HELO nike.apache.org) (192.87.106.230) by apache.org (qpsmtpd/0.29) with ESMTP; Mon, 10 May 2010 18:06:52 +0000 X-ASF-Spam-Status: No, hits=0.7 required=10.0 tests=RCVD_IN_DNSWL_NONE,SPF_NEUTRAL X-Spam-Check-By: apache.org Received-SPF: neutral (nike.apache.org: local policy) Received: from [209.85.222.181] (HELO mail-pz0-f181.google.com) (209.85.222.181) by apache.org (qpsmtpd/0.29) with ESMTP; Mon, 10 May 2010 18:06:43 +0000 Received: by pzk11 with SMTP id 11so1860548pzk.28 for ; Mon, 10 May 2010 11:06:21 -0700 (PDT) Received: by 10.141.124.18 with SMTP id b18mr2899658rvn.202.1273514781133; Mon, 10 May 2010 11:06:21 -0700 (PDT) Received: from [192.168.1.106] ([67.188.70.149]) by mx.google.com with ESMTPS id h11sm2045400rvm.9.2010.05.10.11.06.19 (version=TLSv1/SSLv3 cipher=RC4-MD5); Mon, 10 May 2010 11:06:20 -0700 (PDT) From: Peter Hsu Content-Type: text/plain; charset=us-ascii Content-Transfer-Encoding: quoted-printable Subject: Human readable Cassandra limitations Date: Mon, 10 May 2010 11:06:18 -0700 Message-Id: To: user@cassandra.apache.org Mime-Version: 1.0 (Apple Message framework v1078) X-Mailer: Apple Mail (2.1078) X-Virus-Checked: Checked by ClamAV on apache.org I've seen a lot of threads and posts about why Cassandra is great. I'm = fairly sold on the features, and the few big deployments on Cassandra = give it a lot of credibility. However, I don't believe in magic bullets, so I really want to = understand the potential downsides of Cassandra. Right now, I don't = really have a clue as to what Cassandra is bad at. I took a look at = http://wiki.apache.org/cassandra/CassandraLimitations which is helpful, = but doesn't characterize its weaknesses in ways that I can really = comprehend until I've actually used Cassandra and understand some of the = internals. It seems that the community would benefit from being able to = answer some of these questions in terms of real world use cases. =20 My main questions: * Are there designs in which a SQL database out-performs or out-scales = Cassandra? * Is there a pros vs cons page of Cassandra against an open source SQL = database (MySQL or Postgres)? I do plan on attending the training session next Friday in Palo Alto, = but it'd be great if I had some more food for thought before I attend.