Advanced Queuing - Oracle

General Features of JMS
Example Scenario and Code
In the BooksOnLine example, operations on the OE_neworders_que and
booked_order_topic at the order entry (OE) site can be made faster if the two
topics are associated with different instances. This is done by creating the topics in
different queue tables and specifying different affinities for the queue tables in the
CreateQueueTable() command.
In the example, the queue table OE_orders_sqtab stores queue OE_neworders_
que and the primary and secondary are instances 1 and 2 respectively. For queue
table OE_orders_mqtab stores queue booked_order_topic and the primary
and secondary are instances 2 and 1 respectively. The objective is to let instances 1
& 2 manage the two queues in parallel. By default, only one instance is available. In
this case the owner instances of both queue tables will be set to instance1. However,
if Oracle Real Application Clusters are set up correctly and both instances 1 and 2
are available, then queue table OE_orders_sqtab will be owned by instance 1 and
the other queue table will be owned by instance 2. The primary and secondary
instance specification of a queue table can be changed dynamically using the alter_
queue_table() command as shown in the example that follows. Information about
the primary, secondary and owner instance of a queue table can be obtained by
querying the view USER_QUEUE_TABLES. See "Selecting Queue Tables in User
Schema" in Chapter 10, "Administrative Interface: Views".
/* Create queue tables, topics for OE */
/* createing a queue table to hold queues */
qt_prop = new AQQueueTableProperty("SYS.AQ$_JMS_OBJECT_MESSAGE");
qt_prop.setPrimaryInstance(1);
qt_prop.setSecondaryInstance(2);
q_table = createQueueTable("OE", "OE_orders_sqtab", qt_prop);
/* creating a queue table to hold topics */
qt1_prop = new AQQueueTableProperty("SYS.AQ$_JMS_OBJECT_MESSAGE");
qt1_prop.setMultiConsumer(TRUE);
qt1_prop.setPrimaryInstance(2);
qt1_prop.setSecondaryInstance(1);
q_table1 = createQueueTable("OE", "OE_orders_mqtab", qt1_prop);
dest_prop = new AQjmsDestinationProperty();
queue = ((AQjmsSession)q_sess).createQueue(q_table. "OE_neworders_que",
dest_prop);
dest_prop1 = new AQjmsDestinationProperty();
topic = ((AQjmsSession)q_sess).createTopic(q_table1, "OE_bookedorders_topic",
dest_prop1);
12-20 Oracle9i Application Developer’s Guide - Advanced Queuing