This Article 
 Bibliographic References 
 Add to: 
A Transparent Schema-Evolution System Based on Object-Oriented View Technology
July-August 1997 (vol. 9 no. 4)
pp. 600-624

Abstract—When a database is shared by many users, updates to the database schema are almost always prohibited because there is a risk of making existing application programs obsolete when they run against the modified schema. This paper addresses the problem by integrating schema evolution with view facilities. When new requirements necessitate schema updates for a particular user, then the user specifies schema changes to his personal view, rather than to the shared-base schema. Our view schema-evolution approach then computes a new view schema that reflects the semantics of the desired schema change, and replaces the old view with the new one. We show that our system provides the means for schema change without affecting other views (and thus without affecting existing application programs). The persistent data is shared by different views of the schema, i.e., both old as well as newly developed applications can continue to interoperate. This paper describes a solution approach of realizing the evolution mechanism as a working system, which as its key feature requires the underlying object-oriented view system to support capacity-augmenting views. In this paper, we present algorithms that implement the complete set of typical schema-evolution operations as view definitions. Lastly, we describe the transparent schema-evolution system (TSE) that we have built on top of GemStone, including our solution for supporting capacity-augmenting view mechanisms.

[1] S. Abiteboul and A. Bonner, “Objects and Views,” Proc. ACM-SIGMOD Int'l Conf. Management of Data, pp. 238–247, May 1991.
[2] J. Andany,M. Leonard,, and C. Palisser,“Management of schema evolution in databases,” Proc. Conf. Very Large Databases,Barcelona, Spain, pp. 161-170, Sept. 1991.
[3] J. Banerjee, W. Kim, H.J. Kim, and H.F. Korth, “Semantics and Implementation of Schema Evolution in Object-Oriented Databases,” Proc. ACM-SIGMOD Int'l Conf. Management of Data, pp. 311–322, May 1987.
[4] E. Bertino, “A View Mechanism for Object-Oriented Databases,” Proc. Third Int'l Conf. Extending Database Technology (EDBT), pp. 136–151, Mar. 1992.
[5] S.E. Bratsberg, “Unified Class Evolution by Object-Oriented Views,” Proc. 12th Int'l Conf. the Entity-Relationship Approach (ER), pp. 423–439, Oct. 1992.
[6] P. Butterworth, A. Otis, and J. Stein, "The Gemstone Object Database Mangement System," Comm. ACM, vol. 34, no. 10, Oct. 1991.
[7] S.M. Clamen, "Type Evolution and Instance Adaptation," Technical Report CMU-CS-92-133R, School of Computer Science, Carnegie Mellon Univ., 1992.
[8] D. Fishman, "Iris: An Object Oriented Database Management System," ACM Trans. Office Information Systems, vol. 5, pp. 48-69, Jan. 1987.
[9] H.J. Kim, "Issues in Object-Oriented Database Systems," PhD thesis, Univ. of Texas at Austin, May 1988.
[10] W. Kim and H.-T. Chou, "Versions of Schema for Object-Oriented Databases," Proc. Int'l Conf. Very Large Data Bases, Aug.-Sept. 1988.
[11] H.A. Kuno, Y.G. Ra, and E.A. Rundensteiner, "The Object-Slicing Technique: A Flexible Object Representation and its Evaluation," Technical Report CSE-TR-241-95, Univ. of Michigan, 1995.
[12] H.A. Kuno and E.A. Rundensteiner, "Developing an Object-Oriented View Management System," Proc. Center for Advanced Studies Conf., pp. 548-562, Oct. 1993.
[13] H.A. Kuno and E.A. Rundensteiner, "Materialized Object-Oriented Views in MultiView," ACM Research Issues Data Eng. Workshop, pp. 78-85, Mar. 1995.
[14] H.A. Kuno and E.A. Rundensteiner, "Incremental Update Propagation Algorithms for Materialized Object-Oriented Views in MultiView," to appear in Proc. ICDE'96, 1996.
[15] B.S. Lerner and A.N. Habermann, "Beyond Schema Evolution to Database Reorganization," Proc. OOPSLA, pp. 67-76, 1990.
[16] S. Marche, "Measuring the Stability of Data Models," European J. Information Systems, vol. 2, no. 1, pp. 37-47, 1993.
[17] J. Martin and J. Odell, Object-Oriented Analysis and Design. Prentice Hall, 1992.
[18] A. Mehta, D.L. Spooner, and M. Hardwick, "Resolution of Type Mismatches in an Engineering Persistent Object System," technical report, Computer Science Dept., Rensselaer Polytechnic Inst., 1993.
[19] S. Monk and I. Sommerville, "Schema Evolution in OODBs Using Class Versioning," SIGMOD Record, vol. 22, no. 3, Sept. 1993.
[20] D.J. Penney and J. Stein, "Class Modification in the GemStone Object-Oriented DBMs," Proc. OOPSLA, pp. 111-117, 1987.
[21] Y.-G. Ra, H.A. Kuno, and E.A. Rundensteiner, "A Flexible Object-Oriented Database Model and Implementation for Capacity-Augmenting Views," Technical Report CSE-TR-215-94, Univ. of Michigan, 1994.
[22] Y.-G. Ra and E.A. Rundensteiner, "OODB Support for Providing Transparent Schema Changes," Proc. Center for Advanced Studies Conf., 1994.
[23] Y.-G. Ra and E.A. Rundensteiner, "A Transparent Object-Oriented Schema Change Approach Using View Schema Evolution," Technical Report CSE-TR-211-94, Univ. of Michigan, 1994.
[24] Y.G. Ra and E.A. Rundensteiner, “A Transparent OO Schema Change Approach Using View Schema Evolution,” IEEE Int'l Conf. Data Eng., pp. 165-172, Mar. 1995.
[25] E.A. Rundensteiner, “MultiView: Methodology for Supporting Multiple Views in Object-Oriented Databases,” Proc. 18th Int'l Conf. Very Large Data Bases (VLDB), pp. 187–198, 1992.
[26] E.A. Rundensteiner, "Tools for View Generation in OODBs," Proc. Int'l Conf. Information and Knowledge Management, pp. 635-644, Nov. 1993.
[27] E.A. Rundensteiner, “A Classification Algorithm for Supporting Object-Oriented Views,” Proc. Third Int'l Conf. Information and Knowledge Management (CIKM), pp. 18–25, Nov. 1994.
[28] E.A. Rundensteiner and L. Bic, "Set Operations in New Generation Data Models," IEEE Trans. Knowledge and Data Eng., vol. 4, pp. 382-398, Aug. 1992.
[29] E. Rundensteiner, L. Bic, J. Gilbert, and M.-L. Yin, “Set Restrictions for Semantic Groupings,” IEEE Trans. Knowledge and Data Eng., vol. 6, no. 2, pp. 193-204, Apr. 1994.
[30] C.S. dos Santos, S. Abiteboul, and C. Delobel, “Virtual Schemas and Bases,” Proc. Fifth Int'l Conf. Extending Database Technology (EDBT), pp. 81–94, Mar. 1994.
[31] M.H. Scholl, C. Laasch, and M. Tresch, "Updatable Views in Object-Oriented Databases," Proc. Second DOOD Conf., Dec. 1991.
[32] A.H. Skarra and S.B. Zdonik,“The management of changing types in an object-oriented database,” N. Meyrowitz, ed., Proc. ACM Conf. of Object-Oriented Systems, Languages and Applications(OOPSLA), pp. 483-495,Portland, Ore., Sept. 1986.
[33] M. Tresch and M.H. Scholl, "Schema Transformation without Database Reorganization," SIGMOD Record, pp. 21-27, 1993.
[34] R. Zicari, "A Framework for O2Schema Updates," Building an Object-Oriented Database System: The Story of O2, F. Bancilhon, C. Delobel, and P. Kanellakis, eds., Morgan Kaufmann, 1992.

Index Terms:
Schema evolution, object-oriented view system, interoperability, capacity-augmenting views, software legacy problem, object-oriented database.
Young-Gook Ra, Elke A. Rundensteiner, "A Transparent Schema-Evolution System Based on Object-Oriented View Technology," IEEE Transactions on Knowledge and Data Engineering, vol. 9, no. 4, pp. 600-624, July-Aug. 1997, doi:10.1109/69.617053
Usage of this product signifies your acceptance of the Terms of Use.