Abstract: A delta query technique transmits only latest changes to data of objects from a server to one or more clients in response to a client query (request) to access the object data. A global counter is maintained for all of the objects served by the server. Every time the data of an object changes, a value of the global counter increments (updates) and the updated global counter value is then assumed (“inherited”) by that object. In addition, the global counter is updated when a client issues a request to access one or more objects. If the data of the objects has changed since the last time the client accessed the objects, the server responds with the latest object data and the updated global counter value. Notably, each client maintains a local counter having a value that, upon receipt of the latest object data, is modified to reflect the updated global counter value.

Abstract: 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.