Very interesting question, Alex. Since you've potentially "mutated" the collection you're Iterating, the "correct" thing to do is to invalidate the iterator, but I do see the need to meet your functional requirements of incremental updates.
While I'm not sure it would be ideal, one approach you could possibly take is to do the deletes on another "worker" thread. You could a variety of techniques to get the "work" to those worker thread(s) (queues, etc.), and in theory, the iterator would continue on with its work on the "old" view of the graph. While this could be a big consistency problem for many applications, if you knew that in your application it would not be, it might work. Not sure what happens to iterators in the case of other-thread commits. -----Original Message----- From: [email protected] [mailto:[email protected]] On Behalf Of Alex D'Amour Sent: Friday, July 30, 2010 1:21 PM To: Neo user discussions Subject: [Neo4j] Stability of Iterators Across Transactions? Hello all, I have an application where I have a node that has several hundred thousand relationships (this probably needs to be changed). In the application I iterate over these relationships, and delete a large subset of them. Because there are so many writes, I want to commit the transaction every few thousand deletions. The problem is that the getAllRelationships iterator seems to halt after the first transaction commit. Clearly, I should reduce the number of relationships that are connected to this node, but is this the expected behavior? Should iterators be made stable across transactions, or are they only supposed to be guaranteed within a transaction? Thanks, Alex _______________________________________________ Neo4j mailing list [email protected] https://lists.neo4j.org/mailman/listinfo/user _______________________________________________ Neo4j mailing list [email protected] https://lists.neo4j.org/mailman/listinfo/user
