Caché ObjectScript Reference - InterSystems Documentation

Caché ObjectScript CommandsSee Also• TCOMMIT command• TSTART command• $TLEVEL special variable• Using ObjectScript for Transaction Processing in Using Caché ObjectScriptTSTARTMarks the beginning of a transaction.TSTART:pcTS:pcArgumentspcOptional — A postconditional expression.DescriptionTSTART marks the beginning of a transaction. Following TSTART, database operationsare journaled to enable a subsequent TCOMMIT or TROLLBACK command.TSTART increments the value of the $TLEVEL special variable.Any locks issued within a transaction will be held until the end of the transaction even if thelock is released, unless the lock is specified as short-term. Refer to the LOCK command formore details.Nested TSTART / TCOMMITCaché supports the nesting of the TSTART/TCOMMIT commands, so that modules canissue their TSTART/TCOMMIT pairs correctly, independent of any otherTSTART/TCOMMIT issued in the modules that called them or in the modules they call.The current nesting level of the transaction is tracked by the special variable $TLEVEL.Issuing a TCOMMIT for a nested transaction decrements $TLEVEL, but the actual commitmentof the nested transaction is deferred. A transaction is committed when the outermostmatching TCOMMIT is issued; that is, when $TLEVEL goes back to 0.142 Caché ObjectScript Reference