Inprise Corporation

Kurt Hansen

Anders Hejlsberg

A three-tier data processing system of the present invention includes a client application, operating on a client machine (i.e., first tier), which obtains data from a back-end data source (e.g., database server) by submitting a request (e.g., SQL query) to a middle tier. The middle tier, in turn, comprises a provider and a resolver. Data is actually returned to the client by means of a 'data packet' of the present invention, which is a platform-independent self-describing data format used to exchange data between different subsystems of the architecture. A data packet normally represents a result set, which is received by a client from a remote server, containing both data and metadata. Upon receiving the data packet from the provider, the client unpacks the data and then proceeds to process and manipulate the data as if it were local data (e.g., for insert, deletes, updates, and the like). Additional data packets are provided for special purpose use, including a 'delta' data packet, used when applying client updates, and an 'error' data packet, used to report results (including errors, after a failed update attempt) back to a client. The resolver, upon receiving a delta data packet, applies logic for effecting the user-specified modifications to the data set present at the back end. In the event that the resolver is unable to apply the user-specified modifications, it reports the failed operation back to the client via an error data packet.

Growing community of inventors

Aptos, CA, United States of America

Kurt Hansen