ROLB is used to cancel the database updates. It cancels all the messages that were inserted but not available for transmission. For express PCB, the message is made available for transmission when IMS knows that the message is complete (i.e., when a PURG call is called. For non-express PCB, the message is not made available for transmission until the program reaches a commit point.

In Tuxedo ART for IMS, the simulated ROLB call is used to roll back all the changes made by the application program by using tpabort(), and empty the message buffers that have not been sent out.

For persistent transaction (TP or transaction oriented BMP program), if it is handled by ARTIMPP in persistent mode or handled by ARTIBMPT, ROLB will return the first segment of the first message from last commit point to IOAREA, and delete first message from last commit point in /Q.

For non persistent transaction (TP or Transaction oriented batch), Tuxedo ART for IMS only returns the first segment of the current handling message.