Flat Files

Every business has data that must be organized in a meaningful manner for retrieval and maintenance. These data files started years ago on mainframe computers as flat files.

A flat file was the simpelest structure possible and was a collection of one data record after another in a specified format. The person who created the file chose the length of each field and its position in the record. Anyone using these flat files had to know the length of each field and the order of the fields in the record. The files were read and processed from beginning to end like reading a complete book.

Indexed Files

Then indexed files were invented. The index was maintained in sequence and each index pointed to a record of related data. It was like looking up a person’s address and telephone number in a telephone book.