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Optimization of Complex-Object Queries in PRIMA - Statement of Problems

Harald Schöning

University of Kaiserslautern
P.O.-Box 3049
6750 Kaiserslautern
Federal Republic of Germany
email: schoenin@informatik.uni-kl.de

Full paper (postscript version, compressed by gzip or PDF version )

Abstract

The molecule-atom data model allows the dynamic construction of complex objects using an identifier-reference concept. The model and its implementation in the PRIMA system are sketched. Then, with the help of some sample queries, some alternatives for query evaluation are discussed. The decision among the possible algorithms cannot be based on the standard statistics such as distribution of an attribute value. The kind of information needed is the correlation between graph properties and attribute values. In order to accelerate access, its components may be read in parallel. Using a maximum degree of parallelism for this purpose has disadvantages if the complex object does not qualify with respect to the condition included in the query. Criteria for an optimal degree of parallelism still have to be found.

in: Proc. Dagstuhl-Workshop, 1992