Issues and Considerations

INIT.ORA Parameter

AQ_TM_PROCESSES

A parameter called AQ_TM_PROCESSES should be specified in the init.ora PARAMETER file if you want to perform time monitoring on queue messages. This will be used for messages which have delay and expiration properties specified. This parameter can be set in a range from 0 to 10. Setting it to any other number will result in an error. If this parameter is set to 1, one queue monitor process (QMn) will be created as a background process to monitor the messages. If the parameter is not specified, or is set to 0, the queue monitor process is not created.

Parameter Name:	aq_tm_processes
Parameter Type:	integer
Parameter Class:	Dynamic
Allowable Values:	0 to 10
Syntax:	aq_tm_processes = <0 to 10>
Name of process:	ora_qmn<n>_<oracle sid>
Example:	aq_tm_processes = 1

JOB_QUEUE_PROCESSES

Propagation is handled by job queue (SNP) processes. The number of job queue processes started in an instance is controlled by the init.ora parameter JOB_QUEUE_PROCESSES. The default value of this parameter is 0. In order for message propagation to take place, this parameter must be set to at least 1. The DBA can set it to higher values if there are many queues from which the messages have to be propagated, or if there are many destinations to which the messages have to be propagated, or if there are other jobs in the job queue.

See Also: Oracle8 Reference for complete details about JOB_QUEUE_PROCESSES.

Java AQ API supports both the administrative and operational features of Oracle AQ (Advanced Queueing). In developing Java programs for messaging applications, you will use JDBC to open a connection to the database and then the oracle.AQ, the Java AQ API for message queuing. This means that you will no longer need to use PL/SQL interfaces.