On Tue, Oct 5, 2010 at 8:23 AM, Ian Rogers <ian.rog...@contactclean.com> wrote: > > Does Cassandra have an atomic test-or-set operation? > > That is, I want to check to see if a key has a value and, if not, set it to > something. But it must be an atomic operation - I can't do a separate fetch > and then set from the application as that creates a possible race condition > with another application. > > Equivalent to the SQL "update foo set grum = 'bang' where isnull(grum) ..."
You can (sorta) do this per-row, but you can't scan a whole CF and do this. > Any thoughts how to do this? I think you can probably do what you want with cassandra, but your example is too vague to be sure. -ryan
