Ryan, Independent of this ambiguous requirement what were you thinking about. What I am trying to ask is can you be more specific/concrete about when you can
Simon Reavely On Oct 5, 2010, at 11:30 AM, Ryan King <r...@twitter.com> wrote: > 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
