Distributed database management system

摘要

A distributed database management system provides a central database resident on a server that contains database objects. Objects, e.g., program guide data, to be replicated are gathered together into distribution packages called “slices,” that are transmitted to client devices. A slice is a subset of the central database which is relevant to clients within a specific domain, such as a geographic region, or under the footprint of a satellite transmitter. The viewer selects television programs and Web content from displayed sections of the program guide data which are recorded to a storage device. The program guide data are used to determine when to start and end recordings. Client devices periodically connect to the server using a phone line and upload information of interest which is combined with information uploaded from other client devices for statistical, operational, or viewing models.

主权项

1. A method, comprising:
receiving database objects as first database subsets at a device; storing the database objects on at least one storage device at the device; sending, by the device, a message indicating an inventory of two or more database subsets that were received by the device to a server configured to compare the inventory with a list of database subsets to be sent to the device and transmit second database subsets in the list of database subsets that are not in the inventory to the device; prior to receiving the second database subsets at the device, the device reading, from the at least one storage device, individual database objects that were received in the first database subsets, and using the individual database objects to provide services to users of the device.