Advanced Queuing - Oracle

General Features of Advanced Queuing
Publish-Subscribe Support
PL/SQL (DBMS_AQADM Package): Example Code
SELECT SUM(SO.enq_time - BO.enq_time) / count (*) AVG_PRCS_TIME
FROM WS.AQ$WS_orders_pr_mqtab BO , WS.AQ$WS_orders_mqtab SO
WHERE SO.msg_state = 'PROCESSED' and BO.msg_state = 'PROCESSED'
AND SO.corr_id = BO.corr_id and SO.queue = 'WS_shippedorders_que';
/* Average waiting time in the backed order queue: */
SELECT SUM(BACK.deq_time - BACK.enq_time)/count (*) AVG_BACK_TIME
FROM WS.AQ$WS_orders_mqtab BACK
WHERE BACK.msg_state = 'PROCESSED' AND BACK.queue = 'WS_backorders_que';
Visual Basic (OO4O): Example Code
Use the dbexecutesql interface from the database for this functionality.
Java (JDBC): Example Code
No example is provided with this release.
Advanced Queuing supports the publish-subscribe model of application
integration. In the model, publishing applications put the message in the queue.
The subscribing applications subscribe to the message in the queue. More
publishing and subscribing applications can be dynamically added without
changing the existing publishing and subscribing applications. Advanced Queuing
also supports content-based subscriptions. The subscriber can subscribe to a subset
of messages in the queue based on the message properties and the contents of the
messages. A subscriber to a queue can also be another queue or a consumer on
another queue.
You can implement a publish-subscribe model of communication using Advanced
Queuing as follows:
Set up one or more queues to hold messages. These queues should represent an
area or subject of interest. For example, a queue can be used to represent billed
orders.
Set up a set of rule-based subscribers. Each subscriber may specify a rule which
represents a specification for the messages that the subscriber wishes to receive.
A null rule indicates that the subscriber wishes to receive all messages.
Publisher applications publish messages to the queue by invoking an enqueue
call.
8-28 Oracle9i Application Developer’s Guide - Advanced Queuing