Implementing AQ Asynchronous Messaging

To achieve asynchronous message delivery and processing using AQ (Advanced Queuing), you first need to create a queue and a corresponding queue table in the Oracle database. After that, messages can be inserted into the queue and PL/SQL procedures can be written to handle these messages.

The following are the basic steps for achieving asynchronous message pass and processing using AQ:

1. Create queues and queue tables: You can use the procedures in the DBMS_AQ package to create queues and queue tables. For example, you can use the CREATE_QUEUE_TABLE procedure to create a queue table, and the CREATE_QUEUE procedure to create a queue.
2. Put a message into a queue: Use the DBMS_AQ.ENQUEUE procedure to place a message into the queue. You can pass the content of the message as a parameter to this procedure.
3. Create a handler: Write a PL/SQL procedure to handle messages retrieved from the queue. You can use the DBMS_AQ.DEQUEUE procedure to retrieve messages from the queue and pass them to the handler.
4. Start Processor: You can use the procedure DBMS_AQ.START_CONSUMER to launch a processor that will process messages in the queue in the background.
5. Monitoring and managing queues: Procedures from the DBMS_AQADM package can be used to monitor and manage queues. For example, the PURGE_QUEUE_TABLE procedure can be used to clear messages from a queue table.

By following these steps, it is possible to use AQ in Oracle database to achieve asynchronous message delivery and processing. This approach can be used for scenarios such as asynchronous notifications, queue processing, event-driven situations, and more.