rlebretonnic Software, Support, and Training for Apache Cassandra en-US Wed, 22 May 2013 04:40:22 +0000 http://bbpress.org/?v=1.0.3 q http://www.datastax.com/support-forums/search.php http://www.datastax.com/support-forums/topic/hash-function-for-getting-key-value#post-8476 Thu, 17 Jan 2013 08:15:10 +0000 rlebretonnic 8476@http://www.datastax.com/support-forums/ <p>OK... Thank for your answer.<br /> Basically it is a bad idea to mix Thrift and CQL :-)</p> <p>I also undestood that Cassandra's strategy is CQL according to the 1.2 documentation...</p> <p>Thank again. Regards. </p> http://www.datastax.com/support-forums/topic/hash-function-for-getting-key-value#post-8433 Tue, 15 Jan 2013 21:02:56 +0000 khahn 8433@http://www.datastax.com/support-forums/ <p>Sorry you had trouble finding this info in the docs. Working with pre-CQL-3 applications on <a href="http://www.datastax.com/docs/1.2/ddl/legacy_table" rel="nofollow">http://www.datastax.com/docs/1.2/ddl/legacy_table</a> has some information, but it is sketchy. </p> <p>The column family you created using the CLI is a compact, legacy table (Thrift-compatible), not a CQL 3 table. CQL 3 uses more metadata than Thrift and the metadata won't be there when you try to access the legacy column family using CQL 3. The way CQL 3 deals with this is twofold: CQL3 picks a default name for the row key if none exists. For the row key, that default name is KEY. When you use CQL 3 to query legacy tables with no column names defined for data within a partition, CQL 3 generates the names (column1 and value1) for the data. Row key and cell names are encoded as byte arrays. </p> <p>Please see <a href="http://www.datastax.com/dev/blog/cql3-for-cassandra-experts" rel="nofollow">http://www.datastax.com/dev/blog/cql3-for-cassandra-experts</a> and <a href="http://www.datastax.com/dev/blog/thrift-to-cql3" rel="nofollow">http://www.datastax.com/dev/blog/thrift-to-cql3</a> for all the details. </p> <p>There is no cqlsh function to do what you want to do. </p> http://www.datastax.com/support-forums/topic/hash-function-for-getting-key-value#post-8426 Tue, 15 Jan 2013 15:49:16 +0000 rlebretonnic 8426@http://www.datastax.com/support-forums/ <p>Hi</p> <p>I look for something I didn'd find in doc.<br /> I created a column family and inserted some records using CLI.</p> <p>Now I request it using cqlsh. A technical column named KEY was added by cassandra. The value stored seems to be a hash value for the key used when creating the row within the CLI interface.</p> <p>I can request in cqlsh the column family using :<br /> <pre><code>select * from &lt;CF&gt; where key=&lt;hash value of my rowkey&gt; Is there a function for determining the hash value of the key and make a request like :</code></pre> <p>select * from &lt;CF&gt; where key=hash(&lt;rowkey&gt;)</p> <p>Regards </p>