CHKP is used to set an explicit commit point. At a commit point, IMS/TM commits the changes made by application programs, normally database updates, sends out all the message marked as complete (by PURG for non-express PCB), and retrieves the next input message into the IOAREA provided.

In Tuxedo ART for IMS, the simulated CHKP is used to commit the changes already made by using tpcommit(). The messages that have been marked by complete are sent out. The messages that have not been marked by explicit PURG call are sent out too.

If the transaction is persistent transaction and handled by ARTIMPP in persistent mode or handled by ARTIBMPT, the next message will be retrieved from /Q of this transaction.

If the transaction is not persistent transaction, no next message is retrieved.