When a computer system crashes, the database can be left in a transient state that is damaged. Continuing to use such a database can result in unexpected and undesirable results; including system hangs, incorrect results, the faulty application of business logic, as well as further damage to the database. Journaling can provide for automated recovery and repair of the database, eventually eliminating the need for manual repair.
Advantages of journaling options include:
Automatic "replay" of work to the last committed update recorded in a journal file. Note that with the use of transaction processing and journaling, GT.M provides full ACID properties.
Quick recovery options, such as processing only the information recorded immediately prior to failure.
For example, you can recover just the last minute of work instead of replaying the entire journal file.
Recorded database updates formatted appropriately for processing by an M program.
For example, MUPIP JOURNAL /EXTRACT outputs records specified by time, user, the process identification number, global variable, process name, and transaction type.
Identification of processes active when the system failed.
The /SHOW qualifier identifies these processes, as well as what transactions were not completed, and other information about the database updates and processes contained in the journal file.