You can still get siblings/conflicts even with if_not_modified/If-None-Match because two conflict writes can arrive at the exact same time. It's probably a pretty rare event, but it's worth being aware of because if could cause unexpected things to happen in your application if you aren't aware of the potential.
Combining if_not_modified with PW/PR you could potentially simulate a reasonable approximation of optimistic concurrency control, but you still won't get the serializability enforcement that you would get out of something like serializable snapshot isolation. A better question is: What are you trying to accomplish? Perhaps once we know the overall goal we can tell if you Riak can do what you want. --- Jeremiah Peschka - Managing Director, Brent Ozar PLF, LLC Microsoft SQL Server MVP On Mar 21, 2012, at 12:15 PM, Ransom Richardson wrote: > Does riak support optimistic concurrency? This KB article seems to indicate > not: > https://help.basho.com/entries/321522-can-riak-be-configured-to-fail-an-update-instead-of-generating-a-conflict > > But if it doesn't, what is the meaning of the if_not_modified field in the > PBC Store Object: http://wiki.basho.com/PBC-Store-Object.html? > > If strict quorum is used (as described here: > http://lists.basho.com/pipermail/riak-users_lists.basho.com/2012-January/007157.html) > will that allow optimistic concurrency to be implemented (once the bugs > mentioned in the message are fixed)? Is there any update on those bugs? > > thanks, > Ransom > _______________________________________________ > riak-users mailing list > [email protected] > http://lists.basho.com/mailman/listinfo/riak-users_lists.basho.com _______________________________________________ riak-users mailing list [email protected] http://lists.basho.com/mailman/listinfo/riak-users_lists.basho.com
