Cassandra does not break apart a row. All of the columns of a row are kept on the same nodes.
I believe that writing multiple columns of the same row is transactional, but not atomic. By which I mean that if one column is written all the other ones will be written as well, but if a read happens while the write is being done it is possible that only some of the columns will have the new values. ----- Original Message ----- From: "Don Smith" <dsm...@likewise.com> To: user@cassandra.apache.org Sent: Wednesday, October 5, 2011 2:09:36 PM Subject: Question about sharding of rows and atomicity 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." Will a read from a given node ever return partial results or is the write to a node of a row atomic? Thanks, Don
