A data queue is a type of system object that can be created to send data to one program or process and receive data from another. The data-receiving program may be waiting or may receive the data later.

A data queue is the quickest means to communicate between two jobs.

There are many advantages of using a data queue in as400:

• When sending and receiving data, a data queue requires less overhead than any other method, including database files, message queues, or data areas.
• By calling APIs QSNDDTAQ, QRCVDTAQ, QCLRDTAQ, QMHRDQM, QMHQRDQD, and QMHQCDQ from any high-level program or procedure, we can send, receive, clear, and retrieve the data or description of a data queue and change some attributes of the data queue without having to call any CL programs or exit the High-level program.
• The same data queue can supply data to multiple jobs at once. When we process a lot of entries—more than one job could handle while maintaining performance—we gain some advantage in this situation.
• Every message that is added to a data queue has the option of including the sender ID. The qualified job name and the current user profile are contained in the sender id.
• We can configure the timeout so that, when data is being received from the data queue, the job waits for an entry to appear on the appropriate data queue.
• To restore the data queue to a consistent state if a crash happens, we can journal the data queues.