The offline tester can simulate the TAM service for testing UAP access to TAM files. This facility is called the TAM service simulator.

Files created by the offline tester utftamcre command are handled by the TP1/FS/Table Access file interface. The user must write an offline tester environment definition to associate each logical file name with the actual file.

A TAM file simulated by the offline tester can access the same TAM data files as TP1/FS/Table Access. Indexing is also the same. However, TAM files cannot be accessed by DAM service functions. Also, to reduce shared memory size, only the management and index parts of the TAM file are stored in shared memory and the data part is accessed directly in the TAM file.

At each update request from the UAP, a TAM file simulated by the offline tester is immediately updated (but writing is delayed). If the UAP terminates abnormally or if a rollback request occurs, the TAM file remains in updated status.

File update can be suppressed by option specification when starting the offline tester. Thus, the contents of a TAM file remain unchanged even if the UAP issues an update request function. If the data is re-entered after the update request, the file contents are the same as before the update request.

The user can also specify in the offline tester environment definition whether a lock is to be used for TAM files. Locks can only be placed on files, regardless of any specification made in a function.

Note that the TAM file is not closed when the dc_trn_unchained_commit function is issued in a UAP.

Figure 10-5 outlines the TAM service simulator.

Figure 10-5 Simulating the TAM service