While TSTART and TCOMMIT are generally the preferred way to fence transactions, ZTSTART and ZTCOMMIT commands are also available to fence logical transactions. When an application contains fenced transactions, MUPIP JOURNAL processing treats updates within the transaction as a unit and either restores them completely or not at all.

For more information about ZTSTART and ZTCOMMIT, refer to the "Fencing Transactions" section in this document and also the "Commands" chapter of the GT.M Programmer's Guide.