Borland International, Inc.

David Bredenberg

System and methods are described for integrating the navigational semantic model of PC DBMS environments into the set-oriented model of SQL database environments. More particularly, a Client/Server system of the present invention provides native navigational support on the Server side, without emulation through a multitude of SQL commands from the Client. The Database Server surfaces to the Client an API (Application Programming Interface) having calls corresponding to each verb taken from a navigational context. The Server, in turn, is modified to include knowledge of how to process each navigational verb. To support this functionality, the indexing of the Server is modified to provide bi-directional scrolling. In this manner, the system is able to provide more efficient, higher performance navigational support in an SQL database context.

Client/server database system with methods for providing clients with

Client/server system and methods are described for providing a 'cache range' to database clients. When one or more records in a cache range of a client change, a server in connection with the client sends a notification that the cache range has changed. Instead of the client taking a lock out for updating a record, the client simply indicates to the server which records it is interested in (e.g., via registering an event alerter request), whereupon the server manages its resources as necessary to notify the client of a change in one of the records which is of interest to the client. The server can simply take out 'interest' locks on the corresponding records; these are not locks which exclude the resource from other clients. Other clients are not prevented from accessing this resource (i.e., the records which are of interest). The interest lock is employed in conjunction with the registered event alerter for notifying the client when a range of records of interest is updated by another client. In this manner, the server undertakes action to indicate to the client when the client local buffer might be stale, thereby providing improved local record buffer management in a client/server database context.

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Acton, MA, United States of America

David Bredenberg