Queue Interfaces in the R/2 System 

Definition

On the R/2 host, the queues are stored in a file called DOUT.

Q-API is integrated into the ABAP language and available in the Assembler environment.

Depending on what parameters you set for the Q-API functions, the transfer program is started automatically or must be started manually using the SAP transaction TMQD.

Use

For queue administration, you can use the following transactions:

TMQD:

Use this transaction (Queue display) to display an overview of the queues available in the system and start asynchronous transfer programs with a manual start ID.

TMQM:

This transaction (Queue maintenance) is for the system administrator and should only be available to a limited group. You can use this transaction to change and delete queues.

A queue is treated as a file. It can be opened, written to and closed:

When a queue is opened, the queue attributes are set.

An important feature of the queue write function is that control is returned to the executing program without data transfer having been required to take place. This allows data to be passed to queues from the SAP system online and in update mode.

When all the data is entered in the queue, the queue is closed.

Asynchronous data transfer is implemented in different ways in R/2 Systems. For more details, refer to the following sections:

ABAP key words

ABAP CALLs to Assembler routines