A Classification of Schema Mappings and Analysis of Mapping Tools

摘要: Schema mapping techniques for data exchange have become popular and useful tools both in research industry. A schema relates a source with target via correspondences, which are specified by domain expert possibly supported automated matching algorithms. The set of correspon- dences, i.e., the mapping, is interpreted as transformation usually expressed query. These queries transform from to conform tar- get schema. They can be used materialize at or views virtually integrated system. We present classification situations that occur when between two relational nested (XML) schemata. Our takes into con- sideration 1:1 n:m attribute-level higher-level mappings, special constructs, such choice constraints, cardinality types. Based on this classification, we developed general suite schemata, data, correspondences test ability cope different situations. evaluated several commercial support def- inition mappings interpret transformation. found no tool performs well all many pro- duce incorrect transformations. serve benchmark future improvements developments tools.