On Sun, Dec 11, 2011 at 12:01 PM, Boris Yen <yulin...@gmail.com> wrote: > Hi Sylvain, > > "Writes under the same row key are atomic (even across column families) in > the > sense that they are either all persisted or none are." > > Is this new feature for 1.x, or it also applies to previous version of > Cassandra?
It applies to previous version of Cassandra. -- Sylvain > > Boris > > > On Thu, Dec 8, 2011 at 6:40 PM, Sylvain Lebresne <sylv...@datastax.com> > wrote: >> >> On Thu, Dec 8, 2011 at 12:57 AM, Christof Bornhoevd >> <cbornho...@gmail.com> wrote: >> > Hi All, >> > >> > I'm using Cassandra 1.0.3 (with Hector 0.7). What is the granularity of >> > atomic read and write operations with Cassandra. I.e. is the insert or >> > update of an individual column an atomic operation (in the sense that it >> > either fails or persists completely), or is the insert or update of an >> > entire row in a ColumnFamily atomic? >> > >> > Similarly, if I read multiple columns of the same row, could the read >> > operation interfere with a concurrent write operation on these same >> > columns >> > in a way that I might see some old and some new column values? >> >> Writes under the same row key are atomic (even across column families) in >> the >> sense that they are either all persisted or none are. Note however that it >> is >> possible for a insertion to fail for the client (say you get a >> TimeoutException) but >> for the insertion to still be persisted. >> There is however no isolation currently. It is possible for a read to >> see a state >> where only part of an insertion (even within the same row key) has been >> applied. >> (CASSANDRA-2893 is open to try to add isolation). >> >> -- >> Sylvain >> >> > >> > Cheers and thanks a lot for any kind help on this! >> > Chris > >
