System and method for maintenance and deferred propagation of sc

Details System and method for maintenance and deferred propagation of sc System and method for maintenance and deferred propagation of sc

1995-12-04

1998-08-11

Black, Thomas G.

395611, 395616, G06F 1730

Patent

active

057940304

ABSTRACT:
A method and system for use with object oriented databases provides schema evolution with deferred propagation of schema changes. The method and system provide a schema that persistently maintains class objects by storing an initial class definition, and shape objects associated with particular class objects and storing subsequent class definitions. The shape objects associated with a particular class object form a shape chain, the last shape object in the shape chain being the current shape object, and maintaining the current class definition. Client objects representing actual instances of data in the database, are instantiated from whichever client object or shape object is current at the time of instantiation, so the all newly created client objects always have the current class definition. Existing client objects, which are those that were created prior to one or more subsequent modifications of the class definition and instantiations of the shape objects in the shape chain of the class, are updated to the current class definition only when they are accessed in the database, thereby providing deferred propagation. Updating such client objects includes copying data members for which there was no change in the definition of the member, and performing type conversion on those data members for which there was a change in the definition of the member.

REFERENCES:
patent: 4558413 (1985-12-01), Schmidt et al.
patent: 5241624 (1993-08-01), Torres
patent: 5291593 (1994-03-01), Abraham et al.
patent: 5339438 (1994-08-01), Conner et al.
patent: 5361350 (1994-11-01), Conner et al.
patent: 5392432 (1995-02-01), Engelstad et al.
patent: 5423038 (1995-06-01), Davis
patent: 5437025 (1995-07-01), Bale et al.
patent: 5437027 (1995-07-01), Bannon et al.
patent: 5511188 (1996-04-01), Passucci et al.
patent: 5606661 (1997-02-01), Wear et al.
patent: 5652884 (1997-07-01), Palevich
patent: 5652888 (1997-07-01), Burgess
Clamen, Stewart M., "Data Persistence in Programming Languages", School of Computer Science, Carnegie Mellon University, Technical Report CMU-CS-91-155, May 30, 1991, pp. 2-66.
Morsi, Magdi M.A., Navathe, Shamkant B. and Kim, Hyoung-Joo, "A Schema Management and Prototyping Interface for an Object-Oriented Database Environment", Object Oriented Approach in Information Systems, pp. 157-179.
Lerner, Barbara Staudt and Habermann, A. Nico, "Beyond Schema Evolution to Database Reorganization", ECOOP/OOPSLA '90 Proceedings, Oct. 21-25, 1990, pp. 67-76.
Penney, D. Jason and Stein, J., "Class Modification in the GemStone Object-Oriented DBMS", OOPSLA '87 Proceedings, Oct. 4-8, 1987, pp. 111-117.
Banerjee, Jay, Kim, Won, Kim, Hyoung-Joo and Korth, Henry F. "Semantics and Implementation of Schema Evolution in Object-Oriented Databases", ACM SIGMOD '87 Proceedings, May 1987, pp. 311-322.

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