Advanced Queuing - Oracle

Enqueue Features
}
Time Specification: Expiration
db_conn.commit();
}
catch (Exception ex)
{
System.out.println("Exception " + ex);
}
Messages can be enqueued with an expiration that specifies the interval of time the
message is available for dequeuing. Note that expiration processing requires that
the queue monitor be running. The producer can also specify the time when a
message expires, at which time the message is moved to an exception queue.
Scenario
In the BooksOnLine application, expiration can be used to control the amount of
time that is allowed to process a back order. The shipping application places orders
for books that are not available on a back order queue. If the shipping policy is that
all back orders must be shipped within a week, then messages can be enqueued into
the back order queue with an expiration of 1 week. In this case, any back orders that
are not processed within one week are moved to the exception queue with the
message state set to EXPIRED. This can be used to flag any orders that have not
been shipped according to the back order shipping policy.
PL/SQL (DBMS_AQADM Package): Example Code
CONNECT BOLADM/BOLADM
/* Req-enqueue a back order into a back order queue and set a delay of 7 days;
all back orders must be processed in 7 days or they are moved to the
exception queue: */
CREATE OR REPLACE PROCEDURE requeue_back_order(sale_region varchar2,
backorder order_typ)
AS
back_order_queue_name VARCHAR2(62);
enqopt dbms_aq.enqueue_options_t;
msgprop dbms_aq.message_properties_t;
enq_msgid RAW(16);
BEGIN
/* Look up a back order queue based the the region by means of a directory
service: */
IF sale_region = 'WEST' THEN
8-48 Oracle9i Application Developer’s Guide - Advanced Queuing