title: Oracle AQ same message is delivered twice
body: <p>I created a AQ in oracle and wrote 2 JMS consumers in Java to listen to the queue. I have observed sometimes that if I produce some message in to queue; the count of dequeued messages from queue is greater than what enqueued. It means that some messages are consumed twice.</p>
  
  <p>I have created queue with property:-  <code>multiple_consumers =&gt; FALSE</code></p>
  
  <p>And JMS consumers are working in <code>CLIENT_ACKNOWLEDGE mode</code></p>
  
  <p>Please help me learn the possible reasons for such behavior and it's solution. So, that I can replicate the problem and solve above issue and ensure that the number of message enqueued is equal to number of message dequeued in case of multiple JMS consumers listening to same AQ .</p>