Decomposition of select expressions

G.A. Blaauw, A.J.W. Duijvestijn, F. Nieuwerth

    Research output: Contribution to journalArticleAcademic

    70 Downloads (Pure)

    Abstract

    A select operation that is part of an expression applying to a relational database is decomposed into one or more independent select operations for the purpose of optimising the relational expression. The select expression is treated as a logical expression. From the canonical form of this expression an optimal conjunctive form is obtained which can be decomposed into separate select operations. These separate selects can then be moved to the most effective place within the relational expression. The method also eliminates redundancy in the original expression. A prototype has been used in developing the optimisation method; from this prototype an implementation for use in an actual system has been derived.
    Original languageUndefined
    Pages (from-to)325-330
    JournalInformation systems
    Volume10
    Issue number3
    DOIs
    Publication statusPublished - 1985

    Keywords

    • Relational Databases
    • Information Systems
    • optimisation of relational expressions
    • IR-69396
    • select expressions

    Cite this