Need help to understand a sentence in DSE Cassandra documentation -

Question

http://www.datastax.com/documentation/cassandra/2.0/cassandra/dml/dml_ltwt_transaction_c.html

A SERIAL consistency level allows reading the current (and possibly uncommitted) state of data without proposing a new addition or update. If a SERIAL read finds an uncommitted transaction in progress, it will commit it as part of the read.

What I did not understand is - how can a read operation commit an in progress transaction? Does it mean to say - it will read it as part of the commit?

Answer 1

Thanks for spotting the problem in the docs. The sentence should say, "If a SERIAL read finds an uncommitted transaction in progress, Cassandra will perform a read repair as part of the commit. A read repair updates replicas with the most recent version of frequently-read data.