"bstansberry(a)jboss.com" wrote : You only modify data that you read? What if I just call removeNode() with no preceding get()? | Then the read happens at the time of the removeNode(). I.e., the node to be removed is read from the data structure, then marked as removed and finally removed when the tx completes. "bstansberry(a)jboss.com" wrote : Well, anyway, that makes it clear that MVCC + R_R is not usable for Hibernate Second Level Caching, at least not without a major rewrite of the integration layer. Actually, this should actually be viewed as a bug/inconsistency in the way write skews are currently handled, since: 1. A write skew involving modifying data will overwrite any intermediate data and the last commit wins. 2. In the case of a removeNode(), a write preceeding the remove will win. To be consistent, with the same "last tx wins" approach to dealing with write skews, if write skew checking is disabled a removeNode() should remove *any* node present under the given Fqn, not necessarily the node read earlier in the same tx. View the original post : http://www.jboss.org/index.html?module=bb&op=viewtopic&p=4218732#... Reply to the post : http://www.jboss.org/index.html?module=bb&op=posting&mode=reply&a...