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From Apache Wiki <wikidi...@apache.org>
Subject [Cassandra Wiki] Update of "SecondaryIndexes" by DrewKutcharian
Date Mon, 04 Apr 2011 02:48:08 GMT
Dear Wiki user,

You have subscribed to a wiki page or wiki category on "Cassandra Wiki" for change notification.

The "SecondaryIndexes" page has been changed by DrewKutcharian.
http://wiki.apache.org/cassandra/SecondaryIndexes

--------------------------------------------------

New page:
'''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.

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