Hash Functions
•For example, suppose our search key is a 9-digit employee id number. Our hash function could be as simple as selecting the 4th and last digits to obtain an index into the hash table:
•Therefore, we store the item with a search key 566-99-3411 in our hash table at index 91.
•In this example, we need to be careful which digits we select. Since the first 3 digits of an ID number are based on geography, if we only selected those digits we would be mapping people from the same state into the same location