The difference is that all the cells with the same `id` would belong to the same partition and stored together, so you'd be able to write them atomically and read them together cheaply in a single operation.
What marshray suggested would look like this:
create table bucket.users (name text, field text, value text, primary key ((name, field))); - with a composite partition key. Then you'd have two separate single-cell partitions "jbellis:email" : "jbellis@example.com" and "jbellis:phone" : "555-5555". You don't want to do that in either Riak or Cassandra.
> What marshray suggested would look like this:
create table bucket.users (name text, field text, value text, primary key ((name, field))); - with a composite partition key. Then you'd have two separate single-cell partitions "jbellis:email" : "jbellis@example.com" and "jbellis:phone" : "555-5555". You don't want to do that in either Riak or Cassandra.
Ah I see what you mean. I thought the intent was to group by some unique ID for the user.
They are atomic, they are not isolated. Those are two different properties. The "A" vs the "I" in ACID. http://en.wikipedia.org/wiki/ACID
Edit: Actually, they are isolated in the sense of ACID, doesn't matter what order you do to operations, the answer will be the same. But not isolated the way you want isolated described.
create bucket.users ( id uuid, username text, email text, phone text, primary key (uuid, username) );
That would be exactly how the data was encoded.