Abstract
One of the main characteristics of object-oriented database management systems is the explicit representation of relationships between objects. A simple example for a query addressing these relationships arises, if we assume the object types Company, and Division with the relationship has division from Company to Division. In this case a query might ask for the companies which have a division called “strategy”. The query might start with the companies and navigate to the divisions which can be reached via the has division relationship. Finally the query has to check if the name attribute of the Division object is “strategy”. Since there is no direct condition for the companies in the query, this query execution will be costly. If we assume that there is a reverse relationship division_of from Division to Company, an alternative execution plan might start with the “strategy” divisions and follow this reverse relationship. In this case an index structure for the name attribute of the Division objects can be exploited to speed up query processing.
In the present paper we describe a query optimizer which exploits this potential invertibility of navigational operations in queries. Our approach is based on, but not limited to the context of the ISO and ECMA standard PCTE and P-OQL.
Access this chapter
Tax calculation will be finalised at checkout
Purchases are for personal use only
Preview
Unable to display preview. Download preview PDF.
References
L. Becker and R.H. Güting Rule-based optimization and query processing in an extensible geometric database system. ACM Transactions on Database Systems, 17(2):247–303, Juni 1992.
R. Cattell, editor The Object Database Standard: ODMG-93. Morgan Kaufmann, San Mateo, Cal., USA, 1993.
C.M. Chen and N. Roussopoulos The implementation and performance evaluation of the ADMS query optimizer: Integrating query result caching and matching. In Advances in Database Technology-EDBT’94. 4th Int. Conf. on Extending Database Technology, Proceedings, volume 779 of LNiCS, pages 323–336, Cambridge, UK, 1994.
V. Christophides, S. Cluet, and G. Moerkotte Evaluating queries with generalized path expressions. In Proc. ACM SIGMOD Int. Conf. on Management of Data, pages 413–422, Montreal, Canada, 1996.
D. Comer The ubiquitous B-tree. ACM Computing Surveys, 11(2): 121–137, June 1979.
J.C. Freytag A rule-based view of query optimization. In Proceedings of the ACM SIGMOD Int. Conf. on Management of Data, pages 173–180, San Francisco, Cal., USA, 1987.
J.C. Freytag, D. Maier, and G. Vossen, editors Query Processing for Advanced Database Systems. Morgan Kaufmann, San Mateo, Cal., USA, 1994.
A. Henrich P-OQL: an OQL-oriented query language for PCTE. In Proc. 7th Conf. on Software Engineering Environments, pages 48–60, Noordwijkerhout, Netherlands, 1995. IEEE Computer Society Press.
A. Henrich Document retrieval facilities for repository-based system development environments. In Proc. 19th Annual Int. ACM SIGIR Conf. on Research and Development in Information Retrieval, pages 101–109, Zürich, 1996.
A. Henrich A homogeneous access structure for standard attributes and document representations in vector space. In Proc. 3rd Int. Workshop on Next Generation Information Technologies and Systems, pages 154–161, Jerusalem, Israel, 1997.
A. Henrich and J. Möller Extending a spatial access structure to support additional standard attributes. In Proc. 4th Int. Symp. on Advances in Spatial Databases, volume 951 of LNiCS, pages 132–151, Portland, ME, USA, 1995.
A. Heuer and J. Kröger Query optimization in the CROQUE project. In Proc. 7th Int. Conf. on Database and Expert Systems Applications, volume 1134 of LNiCS, pages 489–499, Zürich, 1996.
Y.E. Ioannidis Query optimization. ACM Computing Surveys, 28(1): 121–123, März 1996.
M.K. Lee, J.Ch. Freytag, and G.M. Lohmann Implementing an interpreter for functional rules in a query optimizer. In Proc. 14th Int. Conf. on Very Large Data Bases, pages 218–229, Los Altos, Cal., USA, 1988.
B. Mitschang Query Processing in Database Systems (Anfrageverarbeitung in Datenbanksystemen). Vieweg Verlag, Braunschweig, Wiesbaden, 1995. in German.
C. Ozkan, A. Dogac, and C. Evrendilek A heuristic approach for optimization of path expressions. In Proc. 6th Int. Conf. on Database and Expert Systems Applications, volume 978 of LNiCS, pages 522–534, London, UK, 1995.
Portable Common Tool Environment-Abstract Specification / C Bindings / Ada Bindings. Standards ECMA-149/-158/-165, 3rd edition, 1993.
Portable Common Tool Environment-Abstract Specification / C Bindings / Ada Bindings. ISO IS 13719-1/-2/-3, 1994.
L. Wakeman and J. Jowett. PCTE-The standard for open repositories. Prentice Hall, Hemel Hempstead, Hertfordshire, UK, 1993.
Author information
Authors and Affiliations
Editor information
Editors and Affiliations
Rights and permissions
Copyright information
© 1999 Springer-Verlag Berlin Heidelberg
About this paper
Cite this paper
Henrich, A., Jamin, S. (1999). On the Optimization of Queries containing Regular Path Expressions. In: Pinter, R.Y., Tsur, S. (eds) Next Generation Information Technologies and Systems. NGITS 1999. Lecture Notes in Computer Science, vol 1649. Springer, Berlin, Heidelberg. https://doi.org/10.1007/3-540-48521-X_6
Download citation
DOI: https://doi.org/10.1007/3-540-48521-X_6
Published:
Publisher Name: Springer, Berlin, Heidelberg
Print ISBN: 978-3-540-66225-9
Online ISBN: 978-3-540-48521-6
eBook Packages: Springer Book Archive