For HBase it's all byte[], so there's currently nothing as involved as what you describe. What happens is that the second Put will overshadow the first one, but both are accessible.
In the future I guess you could implement a coprocessor that does that kind of check, but it's only available in trunk. The closest you could do at the moment would be to do a Get first and then do http://hbase.apache.org/apidocs/org/apache/hadoop/hbase/client/HTable.html#checkAndPut(byte[], byte[], byte[], byte[], org.apache.hadoop.hbase.client.Put) J-D On Thu, Jan 27, 2011 at 1:28 PM, Hiller, Dean (Contractor) <[email protected]> wrote: > Tthere is this really really cool feature in gemfire for conflict > resolution(and I hope hbase has something similar here as it seems so > clean). You can implement an interface that gets called just before the > write to storage that gives you the old value and the new value(and is > single threaded for that row so multiple updates on that row are in same > thread). > > > > Perfect example > > Key="myCar" value=contains people A, B, C version 4 > > > > A put done from node 1 and a put done from node 2 at the same time > > 1. Put people A, B, C, D version 4 > > 2. Put people A, B, C, E version 4 > > > > So the conflict resolver can put 1 fine but then on 2, it can see that > version is 5 on oldValue and can merge A, b, C, E with A, B, C, D > resulting in the full list A, B, C, D, E. this is a dang nice feature. > > > > Does hbase have something similar that one can implement that gets > called on each node out there to do conflict resolution? > > > > Thanks, > > Dean > > > > > > > This message and any attachments are intended only for the use of the > addressee and > may contain information that is privileged and confidential. If the reader of > the > message is not the intended recipient or an authorized representative of the > intended recipient, you are hereby notified that any dissemination of this > communication is strictly prohibited. If you have received this communication > in > error, please notify us immediately by e-mail and delete the message and any > attachments from your system. > >
