Rewrite and Conquer: Dealing with Integrity Constraints in Data Integration

On the Role of Integrity Constraints in Data Integration

We discuss the issue of dealing with integrity constraints over the global schema in data integration. On the one hand, integrity constraints can be used to extract more information from incomplete sources, similarly to the case of databases with incomplete information. On the other hand, integrity constraints raise the problem of dealing with the inconsistency of the whole system, due to contr...

Dealing with Integrity Constraints During Schema Integration

Constraint-aware Schema Transformation

Data schema transformations occur in the context of software evolution, refactoring, and cross-paradigm data mappings. When constraints exist on the initial schema, these need to be transformed into constraints on the target schema. Moreover, when high-level data types are refined to lower level structures, additional target schema constraints must be introduced, such as referential integrity c...

Considering Integrity Constraints During Federated Database Design

Correct transformations and integrations of schemata within the process of federated database design have to encompass existing local integrity constraints. Most of the proposed methods for schema transformation and integration do not sufficiently consider explicit integrity constraints. In this paper we present an approach to deal with integrity constraints. Our approach bases on the idea to r...

ConQuer: A System for Efficient Querying Over Inconsistent Databases

Although integrity constraints have long been used to maintain data consistency, there are situations in which they may not be enforced or satisfied. In this demo, we showcase ConQuer, a system for efficient and scalable answering of SQL queries on databases that may violate a set of constraints. ConQuer permits users to postulate a set of key constraints together with their queries. The system...