Acta Informatica

, Volume 38, Issue 9, pp 621–648 | Cite as

Adding a path connectedness operator to FO+poly (linear)

  • Chris Giannella
  • Dirk Van Gucht
Original article

Abstract.

In the constraint database community FO+poly and FO+linear have been proposed as foundations for spatial database query languages. One of the strengths of this approach is that these languages are a clean and natural generalization of Codd's relational model to a spatial setting. As a result rigorous mathematical study of their expressiveness and complexity can be carried out.

Along this line important geometric queries involving connectivity have been shown to be inexpressible in FO+poly and FO+linear. To address this problem we extend both languages with a parameterized path-connectivity predicate Pconn. We show that FO+linear+Pconn and FO+poly+Pconn[3D] are closed and have PTIME data complexity. We also examine the expressiveness of FO+poly+Pconn and FO+linear+Pconn and show that parity and transitive closure are expressible in each.

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Copyright information

© Springer-Verlag Berlin Heidelberg 2002

Authors and Affiliations

  • Chris Giannella
    • 1
  • Dirk Van Gucht
    • 1
  1. 1.Department of Computer Science, Indiana University, Bloomington, Indiana 47405, USA (e-mail: {cgiannel,vgucht}@cs.indiana.edu) US

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