GT.M provides the JNLFLUSH and JNLWAIT keywords as arguments to the VIEW command. Normal operation does not require VIEW commands to control journaling. However, under special circumstances, such as debugging, VIEW commands with journal keywords allow an M program to ensure that GT.M has transferred all its updates to the journal file(s).

VIEW "JNLFLUSH":region initiates a complete transfer of all buffered journal records for a given region from memory to the disk. Normally, the transfer of journal buffers to disk happens automatically. The transfer is triggered by room requirements to hold new journal records and/or the passage of time since the last update. VIEW "JNLFLUSH" (without a specified region) flushes all regions in the current Global Directory.

VIEW "JNLWAIT" causes GT.M to suspend process execution until all updates initiated by the process in all regions have been transferred to the journal file (on disk). Updates within M TRANSACTIONS typically behave as if they included an implicit VIEW "JNLWAIT" with their final TCOMMIT. TRANSACTIONS with a TRANSACTION ID="BATCH" or "BA" are exempted from the implicit "JNLWAIT". Normally, process execution for updates outside of M transactions continues asynchronously with the transfer of journal records to disk.

For more information on the VIEW command, refer to the "Commands" chapter in the GT.M Programmer's Guide.