Conflation queues replace messages with new one as they arrive if the two messages share the same key value
A conflation queue is created if you specify a <conflationKey> in the XML configuration; or provide a value for x-qpid-conflation-key in the arguments to the Queue.Declare command.
A queue thus created will check incoming messages as they come in for the value in the application headers associated with the given conflationKey. Any message with the same conflation key value which has not yet been dequeued will be dequeued immediately as the new message is inserted into the queue.
Using a non-acquiring consumer (i.e. browsing) one can use a conflation queue as an LVQ which also sends updates as new values are inserted/updated.