This, the 25th issue of Transactions on Large-Scale Data- and Knowledge-Centered Systems, contains five fully revised selected papers focusing on data and knowledge management systems. Topics covered include a framework consisting of two heuristics with slightly different characteristics to compute the action rating of data stores, a theoretical and experimental study of filter-based equijoins in a MapReduce environment, a constraint programming approach based on constraint reasoning to study the view selection and data placement problem given a limited amount of resource, a formalization and an approximate algorithm to tackle the problem of source selection and query decomposition in federations of SPARQL endpoints, and a matcher factory enabling the generation of a dedicated schema matcher for a given schema matching scenario.
On Expedited Rating of Data Stores.- A Theoretical andExperimental Comparison of Filter-Based Equijoins in MapReduce.- ConstraintOptimization Method for Large-Scale Distributed View Selection.- On theSelection of SPARQL Endpoints to Efficiently Execute Federated SPARQL Queries.-YAM: A Step Forward for Generating a Dedicated Schema Matcher.
