Processing Flat Files in Multiple Orders
Sometimes users may want to process flat files in ways that are not readily supported by the file organization.
Consider, for example, the ENROLLMENT records shown in Figure H-1(a). To produce student
schedules, they must be processed in Student Number sequence. But to produce class rosters, the records
need to be processed in Class Number sequence. The records, of course, can be stored in only one
physical sequence. For example, they can be in order on Student Number or on Class Number, but not on
both at the same time. The traditional solution to the problem of processing records in different orders
is to sort them in student order and process the student schedules and then sort the records in class
order and produce class rosters.