Suppose an existing program uses a data base that resides on DASD. The data base contains many records, each one containing personnel information about one employee. Access to the data base is random and programs reference but do not update the records. Each time the program wants to reference a record, it reads the record in from DASD.
If the data base were to exist in a hiperspace, the program would still bring one record into its address space at a time. Instead of reading from DASD, however, the program would bring in the records from the hiperspace on expanded storage (or auxiliary storage, when expanded storage is not available.) In effect, this technique can eliminate many I/O operations and reduce execution time.