Hi, You can’t batch LWT if they don’t work on the same partition. So in your below queries all the values of “id” must be the same.
-- Jacques-Henri Berthemet From: y2k...@gmail.com [mailto:y2k...@gmail.com] On Behalf Of Jimmy Lin Sent: mercredi 27 avril 2016 18:14 To: user@cassandra.apache.org Subject: how expensive is light weight transaction: if not exists hi all, we like to consider using light weight transaction like the following: begin batch: update table set x=y where id=A if not exists; update table set x=y where id=B if not exists; update table set x=y where id=C if not exists; update table set x=y where id=D if not exists; apply batch (using LOCAL_QUORUM) I know there is lot of things going on behind the cass light weight transaction, just how much overhead when using "if not exists" ?
