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Schema Intension Graphs: a Formal Model for the Study of Schema Equivalence

University of Wisconsin--Madison. Computer Sciences DepartmentR. J. Miller

出版	University of Wisconsin-Madison, Computer Sciences Department, 1994
URL	http://books.google.com.hk/books?id=uR_LGwAACAAJ&hl=&source=gbs_api

註釋

Abstract: "We develop a formal data model, the Schema Intension Graph (SIG) model, to aid in understanding the relative information capacity of schemas containing constraints. The basic building blocks of the SIG model are sets that may be combined by the nested application of union and product constructors. The model also permits the expression of binary relations on sets and simple integrity constraints on these relations. We discuss the motivation used in designing the model and establish some fundamental results on the model. We consider the problem of constraint implication in the SIG model and give a sound and complete set of implication rules for a subclass of SIG schemas, called simple SIG schemas.