Database Software

Hi,

I'm a .Net Developer using AQ and I'm a newbie to AQ.

Here is my question:

I'm writing a query which gets all failed/expired messages for a queue. This queue has two subscribers (A and B).

How History table (AQ$_<queue_table>_H ) is updated for the following scenarios
1. When a messages is enqueued
2. When Subscriber A dequeued the message
3. When Subscriber B dequeued
4. When any of the subscriber failed to dequeue the message

Also, I would like to know what entry would be there in exception queue when one fo the subscriber's failed.

Is there any easy way to gather the stats on current messages.

Thanks
Vaddy