Hashed File Organisation
Hashing is the most common form of purely random access to a database or file. It is also used to access columns that do not have an index as an optimisation method. Hash functions determine the address of the page in which the record is to be stored based on one or more fields in the record. The records in a hash file appear randomly distributed across the available space. It needs some hashing algorithm and the method. Hashing Algorithm changes a primary key value into a record address. The mainly popular form of hashing is division hashing with chained overflow.