Preserving Constraints with the Stable Chase

Publikation: Beitrag in Buch/Konferenzbericht/Sammelband/GutachtenBeitrag in KonferenzbandBeigetragenBegutachtung

Abstract

Conjunctive query answering over databases with constraints – also known as (tuple-generating) dependencies – is considered a central database task. To this end, several versions of a construction called chase have been described. Given a set Sigma of dependencies, it is interesting to ask which constraints not contained in Sigma that are initially satisfied in a given database instance are preserved when computing a chase over Sigma. Such constraints are an example for the more general class of incidental constraints, which when added to Sigma as new dependencies do not affect certain answers and might even speed up query answering. After formally introducing incidental constraints, we show that deciding incidentality is undecidable for tuple-generating dependencies, even in cases for which query entailment is decidable. For dependency sets with a finite universal model, the core chase can be used to decide incidentality. For the infinite case, we propose the stable chase, which generalises the core chase, and study its relation to incidental constraints.

Details

OriginalspracheEnglisch
Titel21st International Conference on Database Theory (ICDT 2018)
Seiten12:1-12:19
PublikationsstatusVeröffentlicht - 2018
Peer-Review-StatusJa

Publikationsreihe

ReiheLeibniz international proceedings in informatics : LIPIcs
ISSN1868-8969

Externe IDs

researchoutputwizard legacy.publication#83142
Scopus 85044652855