Three Easy Pieces on Schema Mappings for Tree-structured Data
نویسندگان
چکیده
Schema mappings specify how data organized under a source schema should be reorganized under a target schema. For tree-structured data, the interplay between these specifications and the complex structural conditions imposed by the schemas, makes schema mappings a very rich formalism. Classical data management tasks, well-understood in the relational model, once again become challenging theoretical problems. Recent results on non-mixing integrity constraints help to push the decidability frontier further for three such problems: consistency of mappings, membership in the composition of mappings, and query answering.
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