The ZTSTART command marks the beginning of a logical transaction within a GT.M program. ZTSTART and ZTCOMMIT "fence" transactions (that is, mark the beginning and end). Fenced transactions prevent the MUPIP JOURNAL facility from recovering incomplete transactions. All ZTSTARTs must be matched with ZTCOMMITs before the journal processing facility recognizes the transaction as complete. FIS strongly recommends the use of the M transaction processing commands such as TSTART and TCOMMIT rather than ZTSTART and ZTCOMMIT. FIS no longer tests the deprecated ZTSTART / ZTCOMMIT functionally.
The format of the ZTSTART command is:
The optional truth-valued expression immediately following the command is a command postconditional that controls whether or not GT.M executes the command.
Because ZTSTART has no argument, at least two (2) spaces must follow the command to separate it from the next command on the line.
For more information on Journaling and transaction fencing, refer to the "GT.M Journaling" chapter in the GT.M Administration and Operations Guide.