data, primitive spreadsheets (perhaps comma-separated or tab-delimited), and text files can all be seen as flat-file databases because they lack integrated indexes, built-in references between data elements, and complex data types. Programs to manage collections of books or appointments and address books may use single-purpose flat-file databases, storing and retrieving information from flat-files unadorned with indexes or pointing systems.

While a user can write a table of contents into a text file,