IBM BPM, V8.0.1, All platforms > Authoring services in Integration Designer > Services and service-related functions > Access external services with adapters > Configure and using adapters > IBM WebSphere Adapters > Oracle E-Business Suite > Overview of IBM WebSphere Adapter for Oracle E-Business Suite > Technical overview > Advanced Queue integration overview

Dequeue operation

The Dequeue operation dequeues messages from the advanced queue using PL/SQL or JMS. The dequeued message constituents are payload, message properties, and message ID.

When the dequeue mechanism is PL/SQL, the adapter can retrieve a batch of messages at once instead of one message at every poll cycle, which is the case with JMS dequeue mechanism.

  1. If the dequeue mechanism is JMS, the PollQuantity property is ignored.

  2. If the dequeue mechanism is PL/SQL, the PollQuantity can be up to 500 messages, beyond that you get an exception.

To process the Dequeue operation, the adapter performs the following actions:

  1. Polls the Oracle Advanced Queue and dequeues the messages or events matching the dequeue condition and consumer name from the advanced queue.
  2. Stages the retrieved messages or events into the configured staging table.

  3. Processes each message or event from the staging table, and delivers it to the endpoint.
  4. Updates records in the staging table based on success of message or event delivery.
  5. Deletes the successfully processed events from the staging table.

The table format and content of the staging table is described in the table below:

Definition of the staging table
Column name Type Description
XID VARCHAR Unique transaction ID (XID) value for assured once delivery.
STATUS INTEGER Event status is initially set to a value for a new event and updated by the adapter as it processes the event. The status can have one of the following values:

  • 0: Identifies a new event.
  • 1: Identifies an event that is delivered successfully to endpoint.
  • -1: An error occurred while processing the event.

MSGPROPS CLOB Message properties such as correlation, priority, message state.
PAYLOAD CLOB Message payload.
MSGID VARCHAR Message identifier of the message to be dequeued.
TEXT_LOB CLOB Contains the payload if the size is greater than 4000.

Advanced Queue integration overview


Related tasks:

Configure the module for inbound processing

Configure the module for outbound processing