Quality of mappings for data exchange applications

Abstract

Research has investigated mappings among data sources under two perspectives. On one side, there are studies of practical tools for schema mapping generation; these focus on algorithms to generate mappings based on visual specifications provided by users. On the other side, we have theoretical researches about data exchange. These study how to generate a solution -- i.e., a target instance -- given a set of mappings usually specified as tuple generating dependencies. However, these two research lines have progressed in a rather independent way and we are still far away from having a complete understanding of the properties that a "good" schema mapping system should have; to give an example, there are many possible solutions for a data exchange problem. In fact, there is no consensus yet on a notion of quality for schema mappings. In this thesis, based on concepts provided by schema mapping and data exchange research, we aim at investigate such a notion. Our goal is to identify a fairly general formal context that incorporates the different mapping-generation systems proposed in the literature, and to develop algorithms, tools and methods for characterizing the quality of mappings generated by those systems.