This is only relevant for database operations of entity classes.
This option switches on the on-fail exit point.
If any error occurs in the Data Access Layer (DAL), this function is invoked with a copy of the parameters given to the DAL and a copy of the DAL exception corresponding to the error.
The type of exception depends on the type of error which occurred. The error can either be handled in this exit point or the exception can be thrown from here to allow the error to be handled elsewhere.
For more information on Exit Points, see Exit Points.