Consistent query answers on numerical databases under aggregate constraints

TL;DR

This paper investigates methods for obtaining consistent query answers from numerical databases that violate aggregate constraints, focusing on repair strategies and their computational complexity.

Contribution

It introduces a formal framework for repairing numerical databases under aggregate constraints and analyzes the complexity of computing consistent answers.

Findings

Characterization of repair strategies for aggregate constraints

Complexity results for repairing data and answering queries

Formal framework for consistent query answering under aggregate constraints

Abstract

The problem of extracting consistent information from relational databases violating integrity constraints on numerical data is addressed. In particular, aggregate constraints defined as linear inequalities on aggregate-sum queries on input data are considered. The notion of repair as consistent set of updates at attribute-value level is exploited, and the characterization of several complexity issues related to repairing data and computing consistent query answers is provided.