Mining Violations to Relax Relational Database Constraints

Frequent constraint violations on the data stored in a database may suggest that the represented reality is changing, and thus the database does not reflect it anymore. It is thus desirable to devise methods and tools to support (semi-)automatic schema changes, in order for the schema to mirror the new situation. In this work we propose a methodology and the RELACS tool, based on data mining, to maintain the domain and tuple integrity constraints specified at design time, in order to adjust them to the evolutions of the modeled reality that may occur during the database life. The approach we propose allows to isolate frequent and meaningful constraint violations and, consequently, to extract novel rules that can be used to update or relax the no longer up-to-date integrity constraints. © 2009 Springer Berlin Heidelberg.