Articles/Blogs
A good article by Jonathan Ellis: http://www.datastax.com/dev/blog/whats-new-cassandra-07-secondary-indexes
FAQ for Secondary Indexes
- Q: Are there any limitations beside the hash properties (no between queries)? Like size or memory, etc?
- A: No.
- Q: Are they distributed? If so, how does that work? How are they stored on the nodes?
- A: Each node only indexes data that it holds locally.
- Q: When you write a new row, when/how does the index get updated? What I would like to know is the atomicity of the operation, is the "index write" part of the "row write"?
- A: The row and index updates are one atomic operation.
- Q: Is there a difference between creating a secondary index vs creating an "index" CF manually such as "users_by_country"?
- A: Yes. First, when creating your own index, a node may index data held by another node. Second, updates to the index and data are not atomic.