Re: File update after abnormal program termination

Bummer.  I hate when programmers do that.

Poor mans solution: I suggest you lock the record.  Then, if the job is
somehow terminated, the lock will be removed by the system.  If it's not
feasible to lock exactly that record, then create a surrogate lock file,
write the key to the record there, and then lock it.  If you can lock it,
the record is yours.  If not, another workstation has it - if all programs
are coded to use the same access method.

Whether a database field, or a real record lock is used, you still have
decide how to deal with the 'user went to lunch with a record locked' problem.

One vendors package that I know of clears the 'in use' flag every night at
midnight.  At least then all the records are available again in the morning.

Otherwise, try journaling and commitment control.  If the transaction is
unsuccessful, the system can be set up to roll back the change to the 'in
use' flag, as well as any changes not completed by that session.


>There are programs here that update a field in a file to indicate the record
>(and other associated records that do not have this field updated) is in use
>by workstation.  Trouble is, if the job is ended because of external factors
>like the terminal being shut down or communications between the terminal and
>the controller being terminated, we have to manually reset this field.