The View-Update Problem for Indefinite Databases

TL;DR

This paper develops a formal framework for updating views in indefinite databases with null values, focusing on minimal and grounded repairs that respect the database and view constraints.

Contribution

It introduces a declarative approach to view updates in indefinite databases, formalizing repairs, especially constrained repairs, that minimally and reliably modify the database.

Findings

Formalization of view-update problem for indefinite databases

Definition of constrained repairs that are minimal and grounded

Framework ensures reliable and consistent view updates

Abstract

This paper introduces and studies a declarative framework for updating views over indefinite databases. An indefinite database is a database with null values that are represented, following the standard database approach, by a single null constant. The paper formalizes views over such databases as indefinite deductive databases, and defines for them several classes of database repairs that realize view-update requests. Most notable is the class of constrained repairs. Constrained repairs change the database "minimally" and avoid making arbitrary commitments. They narrow down the space of alternative ways to fulfill the view-update request to those that are grounded, in a certain strong sense, in the database, the view and the view-update request.