Can be only used in conjunction with consecutive numerical keys. If you key value range is 1-1000, you must have records for all 1000 possible keys, that is, your file must have exactly 1000 records. If, for example, you are planning to use student ID numbers as numerical key values and the student id numbers are like 9653421232 (10 digits), you file must contain 9,999,999,999 records and this doesn't make sense. Of course, you should modify the student ID number structure to start from1 and extend till a few thousand.
This disadvantage (only numerical and consecutive values for the key value) is overcome with a completely different file structure, nameky the INDEXED SEQUENTIAL FILE.
This disadvantage (only numerical and consecutive values for the key value) is overcome with a completely different file structure, nameky the INDEXED SEQUENTIAL FILE.
