XML schema mappings using schema constraints and Skolem functions
[ 1 ] Instytut Automatyki i Inżynierii Informatycznej, Wydział Elektryczny, Politechnika Poznańska | [ P ] employee
2008
chapter in monograph
english
EN A schema mapping is an executable specification describing transformation of data structured under different schemas. In this paper we discuss the problem of automatic generation of XML schema mappings using information provided by schemas and correspondences between schemas. Mappings are specified in a mapping language XDMap whose constructs are based on Skolem functions. We use Skolem functions with text-valued arguments from a source instance to create nodes in the target instance, and to specify functional dependencies between some values. First, using constraints defined within a schema, an algorithm produces the automapping representing this schema. Next, (auto)mappings can be combined by means of some operators delivering more general mappings between schemas provided that a correspondence between schemas is given. While a mapping is executed, some missing data can be inferred based on constraints encoded in the mapping specification.
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