The Fixpoint Bounded-Variable Queries are PSPACE-Complete

Forfattere

  • Stefan Dziembowski

DOI:

https://doi.org/10.7146/brics.v3i41.20023

Resumé

We study complexity of the evaluation of fixpoint bounded-variable
queries in relational databases. We exhibit a finite database such
that the problem whether a closed fixpoint formula using only 2 individual variables is satisfied in this database is PSPACE-complete. This clarifies the issues raised by Moshe Vardi in [Var95]. We study also the complexity of query evaluation for a number of restrictions of fixpoint logic. In particular we exhibit a sublogic for which the upper bound postulated by Vardi holds.

Downloads

Publiceret

1996-06-11

Citation/Eksport

Dziembowski, S. (1996). The Fixpoint Bounded-Variable Queries are PSPACE-Complete. BRICS Report Series, 3(41). https://doi.org/10.7146/brics.v3i41.20023

Nummer

Nr. 41 (1996): RS-41 The Fixpoint Bounded-Variable Queries are PSPACE-Complete

Sektion

Artikler

Licens

Authors who publish with this journal agree to the following terms:

    1. Authors retain copyright and grant the journal right of first publication with the work simultaneously licensed under a Creative Commons Attribution License that allows others to share the work with an acknowledgement of the work's authorship and initial publication in this journal.

    1. Authors are able to enter into separate, additional contractual arrangements for the non-exclusive distribution of the journal's published version of the work (e.g., post it to an institutional repository or publish it in a book), with an acknowledgement of its initial publication in this journal.

  1. Authors are permitted and encouraged to post their work online (e.g., in institutional repositories or on their website) prior to and during the submission process, as it can lead to productive exchanges, as well as earlier and greater citation of published work (See The Effect of Open Access).