License: Creative Commons Attribution 3.0 Unported license (CC BY 3.0)
When quoting this document, please refer to the following
DOI: 10.4230/LIPIcs.ICDT.2019.19
URN: urn:nbn:de:0030-drops-103217
URL: http://dagstuhl.sunsite.rwth-aachen.de/volltexte/2019/10321/
Go to the corresponding LIPIcs Volume Portal

Berger, Gerald ; Otto, Martin ; Pieris, Andreas ; Surinx, Dimitri ; Van den Bussche, Jan

Additive First-Order Queries

pdf-format:
LIPIcs-ICDT-2019-19.pdf (0.5 MB)

Abstract

A database query q is called additive if q(A U B) = q(A) U q(B) for domain-disjoint input databases A and B. Additivity allows the computation of the query result to be parallelised over the connected components of the input database. We define the "connected formulas" as a syntactic fragment of first-order logic, and show that a first-order query is additive if and only if it expressible by a connected formula. This characterisation specializes to the guarded fragment of first-order logic. We also show that additivity is decidable for formulas of the guarded fragment, establish the computational complexity, and do the same for positive-existential formulas. Our results hold when restricting attention to finite structures, as is common in database theory, but also hold in the unrestricted setting.

BibTeX - Entry

@InProceedings{berger_et_al:LIPIcs:2019:10321,
  author =	{Gerald Berger and Martin Otto and Andreas Pieris and Dimitri Surinx and Jan Van den Bussche},
  title =	{{Additive First-Order Queries}},
  booktitle =	{22nd International Conference on Database Theory (ICDT 2019)},
  pages =	{19:1--19:14},
  series =	{Leibniz International Proceedings in Informatics (LIPIcs)},
  ISBN =	{978-3-95977-101-6},
  ISSN =	{1868-8969},
  year =	{2019},
  volume =	{127},
  editor =	{Pablo Barcelo and Marco Calautti},
  publisher =	{Schloss Dagstuhl--Leibniz-Zentrum fuer Informatik},
  address =	{Dagstuhl, Germany},
  URL =		{http://drops.dagstuhl.de/opus/volltexte/2019/10321},
  doi =		{10.4230/LIPIcs.ICDT.2019.19},
  annote =	{Keywords: Expressive power}
}

Keywords: Expressive power
Collection: 22nd International Conference on Database Theory (ICDT 2019)
Issue Date: 2019
Date of publication: 19.03.2019

DROPS-Home | Fulltext Search | Imprint | Privacy Published by LZI