Abstract

In order to deal with inconsistent databases, a repair semantics defines a set of admissible database instances that restore consistency, while staying close to the original instance. This set can be used to characterize consistent data and consistent query answers in inconsistent databases. In this work we present a repair semantics for spatial databases and spatial integrity constraints, i.e. constraints that combine semantic and topological aspects of spatial data. We also propose the notion of consistent answer to a spatial conjunctive query. This introduces the idea of inconsistency tolerance in the spatial domain, shifting the goal from the consistency of a spatial database to the consistency of query answers. Copyright 2008 ACM.