A method performed by a processor allows an individual to update or maintain a database including a core and an extension. The core contains core tables including general data and the extension contains extension tables including specific data. The core tables and the extension tables have the same primary keys and the specific data are an extension of the general data. The method includes receiving an input from the individual for modifying the database, modifying the core using the received input, and automatically modifying the extension to reflect the modifying of the core.