Advanced Queuing - Oracle

For details on XMlType operations refer to Application Developer's guide - XML
Define transformations to convert Oracle objects to XMLType.
General Features of Advanced Queuing
See Also: Oracle9i XML Database Developer’s Guide - Oracle XML
DB for details on XMLType operations
Define rule-based subscribers that query message content using XMLType
operators such as XMLType.existsNode() and XMLType.extract().
In the BooksOnline application, assume that the Overseas Shipping site represents
the order as SYS.XMLType. The Order Entry site represents the order as an Oracle
object, ORDER_TYP.
The Overseas queue table and queue are created as follows:
BEGIN
dbms_aqadm.create_queue_table(
queue_table => 'OS_orders_pr_mqtab',
comment => 'Overseas Shipping MultiConsumer Orders queue table',
multiple_consumers => TRUE,
queue_payload_type => 'SYS.XMLTtype',
compatible => '8.1');
END;
BEGIN
dbms_aqadm.create_queue (
queue_name => 'OS_bookedorders_que',
queue_table => 'OS_orders_pr_mqtab');
END;
Since the representation of orders at the Overseas Shipping site is different from the
representation of orders at the Order Entry site, a transformation is applied before
messages are propagated from the Order Entry site to the Overseas Shipping site.
/* Add a rule-based subscriber (for Overseas Shipping) to the Booked orders
queues with Transformation. Overseas Shipping handles all non-US orders: */
DECLARE
subscriber aq$_agent;
BEGIN
subscriber := aq$_agent('Overseas_Shipping','OS.OS_bookedorders_que',null);
dbms_aqadm.add_subscriber(
queue_name => 'OE.OE_bookedorders_que',
subscriber => subscriber,
rule => 'tab.user_data.orderregion = ''INTERNATIONAL''',
transformation => 'OS.OE2XML');
END;
A Sample Application Using AQ 8-15