This Article 
   
 Share 
   
 Bibliographic References 
   
 Add to: 
 
Digg
Furl
Spurl
Blink
Simpy
Google
Del.icio.us
Y!MyWeb
 
 Search 
   
An Evaluation of Vertical Class Partitioning for Query Processing in Object-Oriented Databases
September/October 2002 (vol. 14 no. 5)
pp. 1095-1118

Abstract—Vertical partitioning is a design technique for reducing the number of disk accesses to execute a given set of queries by minimizing the number of irrelevant instance variables accessed. This is accomplished by grouping the frequently accessed instance variables as vertical class fragments. The complexity of object-oriented database models due to subclass hierarchy and class composition hierarchy complicates the definition and representation of vertical partitioning of the classes, which makes the problem of vertical partitioning in OODBs very challenging. In this paper, we develop a comprehensive analytical cost model for processing of queries on vertically partitioned OODB classes. A set of analytical evaluation results is presented to show the effect of vertical partitioning, and to study the trade-off between the projection ratio versus selectivity factor vis-a-vis sequential versus index access. Furthermore, an empirical experimental prototype supporting vertical class partitioning has been implemented on a commercial OODB tool kit to validate our analytical cost model.

[1] S. Bhar and K. Barker, “Static Allocation in Distributed Objectbase Systems: A Graphical Approach,” Proc. Information Systems and Data Management, Sixth Int'l Conf. (CISMOD '95), pp. 92-114, Nov. 1995.
[2] E. Bertino and W. Kim, “Indexing Technique for Queries on Nested Objects,” IEEE Trans. Knowledge and Data Eng., vol. 1, no. 2, pp. 196-214, 1989.
[3] D. Comer, “The Ubiquitous B-Tree,” ACM Computing Surveys, vol. 11, no. 2, pp. 121-137, June 1979.
[4] D.W. Cornell and P.S. Yu, “A Vertical Partitioning Algorithm for Relational Databases,” Proc. Data Eng., 1987.
[5] C. Ezeife and K. Barker, “Distributed Object Based Design: Vertical Fragmentation of Classes,” Int'l J. Distributed and Parallel Databases, vol. 6, no. 4, pp. 327-360, Oct. 1998.
[6] C.W. Fung, K. Karlapalem, and Q. Li, “An Analytical Approach Towards Evaluating Method-Induced Vertical Partitioning Algorithms,” Technical Report HKUST-CS96-33, HKUST, available fromhttp://yeroos.isys.ucl.ac.be/file.pdf/P-02-01.pdfhttp:/ www.cs.ust.hk, 1996.
[7] C.W. Fung, K. Karlapalem, and Q. Li, “Cost-Driven Evaluation of Vertical Partitioning in Object-Oriented Databases,” Proc. Fifth Int'l Conf. Database Systems for Advanced Applications, pp. 11-20, 1997. Also as an extended version technical report HKUST-CS96-32, HKUST, available from.
[8] C.W. Fung, K. Karlapalem, and Q. Li, “Cost-Driven Vertical Class Partitioning for Methods in Object Oriented Databases,” submitted to VLDB J., 2000.
[9] G. Gardarin, J.-R. Gruser, and Z.-H. Tang, “A Cost Model for Clustered Object-Oriented Databases,” Proc. Very Large Data Base Conf. '95, pp. 323-334, 1995.
[10] A. Kemper and G. Moerkotte, “Access Support in Object Bases,” Proc. ACM-SIGMOD Int'l Conf. Management of Data, pp. 364-374, 1990.
[11] K. Karlapalem, S.B. Navathe, and M.A. Morsi, “Issues in Distribution Design of Object Oriented Databases,” Distributed Object Management, Morgan-Kauffman, pp. 148-164, 1994.
[12] K. Karlapalem and Q. Li, “Partitioning Schemes for Object Oriented Databases,” Proc. Fifth Int'l Workshop Research Issues in Data Eng. (RIDE-DOM '95), pp. 42-49, 1995.
[13] K. Karlapalem, Q. Li, and S. Vieweg, “Method Induced Partitioning Schemes in Object Oriented Databases,” Proc. 16th Int'l Conf. Distributed Computing System (ICDCS '96), 1996.
[14] Neologic Systems, Inc., NeoAccess Developer's Reference Manual (Version 4.1). 1996.
[15] S.B. Navathe, S. Ceri, G. Wiederhold, and J. Dou, “Vertical Partitioning Algorithms for Database Design,” ACM Trans. Database Systems, vol. 9, no. 4, 1984.
[16] H.K. Wong and K.W. Yiu, “Vertical Partitioning in Object Oriented Databases,” Undergraduate Final Year Project, Dept. of Computer Science, HKUST, Dec. 1996.
[17] S.B. Yao, "Approximating Block Accesses in Database Organizations," Comm. ACM, vol. 20, no. 4, pp. 260-261, Apr. 1977.

Index Terms:
Class partitioning, vertical partitioning, query processing, object-oriented databases, analytical cost model.
Citation:
Chi-wai Fung, Kamalakar Karlapalem, Qing Li, "An Evaluation of Vertical Class Partitioning for Query Processing in Object-Oriented Databases," IEEE Transactions on Knowledge and Data Engineering, vol. 14, no. 5, pp. 1095-1118, Sept.-Oct. 2002, doi:10.1109/TKDE.2002.1033777
Usage of this product signifies your acceptance of the Terms of Use.