Task 2: Configuring a Queue and a Messaging Client

Create a queue table and a queue to store the messages that the first application will generate for the second application. After the queue is created, message notification requires a consumer who can dequeue messages from the queue. In this example, a messaging client is the consumer who can dequeue messages from the streams_queue queue.

To configure a queue and a messaging client: 

1. Create a queue named streams_queue in the schema of the Oracle Streams administrator. See "Creating an ANYDATA Queue" for instructions.

2. On a command line, open SQL*Plus and connect to the database as the Oracle Streams administrator.

   See Starting SQL*Plus and Connecting to the Database for more information about starting SQL*Plus.

3. Create a messaging client to enable the Oracle Streams administrator to dequeue messages from the streams_queue queue:

   BEGIN
     DBMS_STREAMS_ADM.ADD_MESSAGE_RULE (
       message_type   => 'strmadmin.app_info',
       rule_condition => ':MSG.VALUE >= 0',
       streams_type   => 'DEQUEUE',
       streams_name   => 'strmadmin',
       queue_name     => 'strmadmin.streams_queue');
   END;
   /
   

   The user name for the Oracle Streams administrator must be specified for the streams_name parameter. In this example, the user name for the Oracle Streams administrator is strmadmin. The name of the new messaging client is also strmadmin.

   A messaging client uses rules to determine which messages to dequeue. In this example, the rule for the messaging client specifies that all messages with a value greater than zero should be dequeued. So, with this rule, the messaging client will dequeue all new messages of type strmadmin.app_info that appear in strmadmin.streams_queue because all parameter values are greater than or equal to zero.

4. Complete the steps in "Task 3: Configuring a Mechanism for Dequeuing Messages" to continue this extended example.