Cassandra atomic reads/writes within a single ColumnFamily -

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cassandra's front page http://incubator.apache.org/cassandra/ states that:

cassandra guarantees reads , writes atomic within single columnfamily.

what mean?
sounds means batch_insert() , batch_mutate() of two different rows, in same cf atomic , if operation on 1 of rows fails, whole operation fails. sounds true... correct?

i have answer jonathan ellis, cassandra maintainer:

it's correct, if understood correctly. should remove since it's confusing written.

what means is, if write given row acked, eventually, all data updated in row available reads. no, it's not atomic @ batch_mutate level @ list level.


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