Semantic Classifications of Queries to Relational Databases

  • José María Turull Torres
Conference paper

DOI: 10.1007/3-540-36596-6_11

Part of the Lecture Notes in Computer Science book series (LNCS, volume 2582)
Cite this paper as:
Torres J.M.T. (2003) Semantic Classifications of Queries to Relational Databases. In: Bertossi L., Katona G.O.H., Schewe KD., Thalheim B. (eds) Semantics in Databases. SiD 2001. Lecture Notes in Computer Science, vol 2582. Springer, Berlin, Heidelberg

Abstract

We survey different semantic classifications of queries to relational databases, as well as the different systems of partial isomorphisms developed as algebraic (hence, semantic) characterizations of equality of theories for databases, in FO and in weaker logics. We introduce an abstract notion of similarity for databases, as equality in the theories for a given logic and we define different sub-classes of queries by requiring that the queries in a given sub-class should not distinguish between databases which are similar. Then we use this general strategy to present a new semantic classification, with the class of bounded variable logics with counting (Ck), as the target logics. One important consequence of the definition of the two semantic classifications of queries which we present here is their orthogonality with the TIME-SPACE hierarchy defined in Turing machine complexity, allowing the definition of finer complexity classes by intersecting orthogonal hierarchies.

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Copyright information

© Springer-Verlag Berlin Heidelberg 2003

Authors and Affiliations

  • José María Turull Torres
    • 1
  1. 1.Department of Information SystemsMassey University Information Science Research CentreWellingtonNew Zealand

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