What is a queue?

A queue is a data structure used to store messages. The messages are put on the queue by application programs, or by a queue manager as part of its normal operation.

Each queue is owned by a queue manager. The queue manager maintains the queues it owns and stores all the messages it receives onto the appropriate queues.

WebSphere MQ Version 6 supports queues over 2 GB in size; Enabling large queues discusses this in more detail. For information about planning the amount of storage you need for queues, visit the WebSphere MQ Web site for platform-specific performance reports:

http://www.ibm.com/software/ts/mqseries/

Predefined queues and dynamic queues

Queues can be characterized by the way that they are created:

For further information about MQSC, see WebSphere MQ Script (MQSC) Command Reference.

Retrieving messages from queues

Suitably authorized applications can retrieve messages from a queue according to the following retrieval algorithms:

The MQGET request from the application determines the method used.