When your database applications perform actions on
your database files, you should monitor messages about file errors that the
program detected so that you can take the proper actions to prevent the errors.
Each high-level language (HLL) provides its own procedure for monitoring
these messages, and you should see the documentation for the HLL you are using
to implement error message monitoring.
One or more of the following events occur when error conditions are detected
during processing of a database file:
- Messages can be sent to the program message queue for the program processing
the file.
- An inquiry message can be sent to the system operator message queue.
- File errors and diagnostic information can appear to your program as return
codes and status information in the file feedback area.
For example, the
COBOL language
sets a return code in the file status field if it is defined in the program.