Estimating Costs of Path Expression Evaluation in Distributed Object Databases

  • Gabriela Ruberg
  • Fernanda Baião
  • Marta Mattoso
Conference paper
Part of the Lecture Notes in Computer Science book series (LNCS, volume 2453)

Abstract

Efficient evaluation of path expressions in distributed object databases involves choosing among several query processing strategies, due to the rich semantics involved in object-based data models and to the complexity added by the distribution. This work presents a new cost model for object-based query processors and addresses relevant issues, which are ignored or relaxed in other works in the literature, such as the selectivity of the path expression, the sharing degree of the referenced objects, the partial participation of the collections in the relationships, and the distribution of the database objects across the nodes of a network. These issues allowed us to present more realistic estimates for the query optimizer. Our cost model has been validated against experimental results obtained with an object DBMS prototype running in a distributed architecture, using the OO7 benchmark application.

Preview

Unable to display preview. Download preview PDF.

Unable to display preview. Download preview PDF.

References

  1. 1.
    Bellatreche, L., Karlapalem, K., Basak, G.: Query-Driven Horizontal Class Partitioning for Object-Oriented Databases. DEXA 1998, 692–701Google Scholar
  2. 2.
    Bellatreche, L., Karlapalem, K., Li, Q.: Derived Horizontal Class Partitioning in OODBs: Design Strategies, Analytical Model and Evaluation. ER 1998, 465–479Google Scholar
  3. 3.
    Bertino, E., Foscoli, P.: On Modeling Cost Functions for Object-Oriented Databases. IEEE TKDE 9(3), 500–508 (1997)Google Scholar
  4. 4.
    Carey, M., De Witt D., Naughton, J.: The OO7 Benchmark. ACM SIGMOD 22(2), 12–21 (1993)CrossRefGoogle Scholar
  5. 5.
    Cho, W., Park, C., Whang, K., Son, S.: A New Method for Estimating the Number of Objects Satisfying an Object-Oriented Query Involving Partial Participation of Classes. Information Systems 21(3), 253–267 (1996)CrossRefGoogle Scholar
  6. 6.
    Deutsch, A., Fernandez, M., et al.: Querying XML Data. IEEE Data Engineering Bulletin 22(3), 10–18 (1999)Google Scholar
  7. 7.
    Ezeife, C., Zheng, J.: Measuring the Performance of Database Object Horizontal Fragmentation Schemes. IDEAS 1999, 408–414Google Scholar
  8. 8.
    Fung, C. Karlapalem, K., Li, Q.: Cost-driven evaluation of vertical class partitioning in object oriented databases. DASFAA 1997, 11–20Google Scholar
  9. 9.
    Gardarin, G., Gruser, J., Tang, Z.: A Cost Model for Clustered Object-Oriented Databases. VLDB 1995, 323–334Google Scholar
  10. 10.
    Gardarin, G., Gruser, J., Tang, Z.: Cost-based Selection of Path Expression Processing Algorithms in Object-Oriented Databases. VLDB 1996, 390–401Google Scholar
  11. 11.
    Kossmann, D.: The State of the Art in Distributed Query Processing. ACM Computing Surveys 32(4), 422–469 (2000)CrossRefGoogle Scholar
  12. 13.
    Ozkan, C., Dogac, A., Altinel, M.: A Cost Model for Path Expressions in Object Oriented Queries. Journal of Database Management 7(3), 25–33 (1996)Google Scholar
  13. 14.
    Ruberg, G.: A Cost Model for Query Processing in Distributed-Object Databases, M.Sc. Thesis in Portuguese, COPPE/UFRJ, Brazil (2001). Reduced version in English available in http://www.cos.ufrj.br/~gruberg/ruberg2001_english.pdf
  14. 15.
    Tavares, F.O., Victor, A.O., Mattoso, M.: Parallel Processing Evaluation of Path Expressions. SBBD 2000, 49–63Google Scholar

Copyright information

© Springer-Verlag Berlin Heidelberg 2002

Authors and Affiliations

  • Gabriela Ruberg
    • 1
  • Fernanda Baião
    • 1
  • Marta Mattoso
    • 1
  1. 1.Department of Computer ScienceCOPPE/UFRJRio de JaneiroBrazil

Personalised recommendations