On Tue, Dec 15, 2009 at 5:19 PM, Brian Burruss <bburruss@real.com> wrote:
can the cassandra client (java specifically) specify that a particular "put" should be "create only, do not update"?  If the value already exists in the database, i want the put to fail.  for instance, two users want the exact same username, so they both do a "get" to determine if the username already exists, it doesn't, so they create.  the last one to create wins, correct?

Correct.  You would need to implement a locking mechanism such as Zookeeper  in your application to get around this.