Optimizing Queries with Object Updates

  • Authors:

  • Leonidas Fegaras

  • Affiliations:

  • Department of Computer Science and Engineering, The University of Texas at Arlington, 416 Yates Street, P.O. Box 19015, Arlington, TX 76019-19015. fegaras@cse.uta.edu

  • Venue:
  • Journal of Intelligent Information Systems - Special issue on functional approach to intelligent information systems
  • Year:
  • 1999

Quantified Score

Hi-index 0.00

Visualization

Abstract

Object-oriented databases (OODBs) provide powerful dataabstractions and modeling facilities but they usually lack a suitableframework for query processing and optimization. Even though thereis an increasing number of recent proposals on OODB queryoptimization, only few of them are actually focused on queryoptimization in the presence of object identity and destructiveupdates, features often supported by most realistic OODB languages. This paper presents a formal framework for optimizing object-orientedqueries in the presence of side effects. These queries may containobject updates at any place and in any form. We present a languageextension to the monoid comprehension calculus to express theseobject-oriented features and we give a formal meaning to theseextensions. Our method is based on denotational semantics, which isoften used to give a formal meaning to imperative programminglanguages. The semantics of our language extensions is expressed interms of our monoid calculus, without the need of any fundamentalchange to our basic framework. Our method not only maintainsreferential transparency, which allows us to do meaningful queryoptimization, but it is also practical for optimizing OODB queriessince it allows the same optimization techniques applied to regularqueries to be used with minimal changes for OODB queries withupdates.