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Subject: Exactly one wide row per node for a given CF?
Message-Id: <17D87E4D-6D94-4891-9860-94FC4E777ED6@gmail.com>
Date: Mon, 2 Dec 2013 21:09:13 -0800
To: user@cassandra.apache.org
Mime-Version: 1.0 (Mac OS X Mail 7.0 \(1822\))

Subject says it all. I want to be able to randomly distribute a large =
set of records but keep them clustered in one wide row per node.

As an example, lets say I=92ve got a collection of about 1 million =
records each with a unique id. If I just go ahead and set the primary =
key (and therefore the partition key) as the unique id, I=92ll get very =
good random distribution across my server cluster. However, each record =
will be its own row. I=92d like to have each record belong to one large =
wide row (per server node) so I can have them sorted or clustered on =
some other column.

If I say have 5 nodes in my cluster, I could randomly assign a value of =
1 - 5 at the time of creation and have the partition key set to this =
value. But this becomes troublesome if I add or remove nodes. What =
effectively I want is to partition on the unique id of the record =
modulus N (id % N; where N is the number of nodes).

I have to imagine there=92s a mechanism in Cassandra to simply randomize =
the partitioning without even using a key (and then clustering on some =
column).

Thanks for any help.=