Subsumption and complementation as data fusion operators

The goal of data fusion is to combine several representations of one real world object into a single, consistent representation, e.g., in data integration. A very popular operator to perform data fusion is the minimum union operator. It is defined as the outer union and the subsequent removal of subsumed tuples. Minimum union is used in other applications as well, for instance in database query optimization to rewrite outer join queries, in the semantic web community in implementing SPARQL’s OPTIONAL operator, etc. Despite its wide applicability, there are only few efficient implementations, and until now, minimum union is not a relational database primitive. This paper fills this gap as we present implementations of subsumption that serve as a building block for minimum union. Furthermore, we consider this operator as database primitive and show how to perform optimization of query plans in presence of subsumption and minimum union through rule-based plan transformations. Experi...

• Type: Conference
• Year: 2010
• Where: EDBT
• Authors: Jens Bleiholder, Sascha Szott, Melanie Herschel, Frank Kaufer, Felix Naumann
• Keywords: Data Fusion, Database, EDBT 2010, Minimum Union, Minimum Union Operator