Abstract

) Mengchi Liu Department of Computer Science University of Regina Regina, Saskatchewan, Canada S4S 0A2 mliu@cs.uregina.ca Abstract This paper presents a novel logic-based language for nested relations. It stands in the same relationship to the nested relation model as Datalog stands to the relational model. The main novelties of the language are the mechanisms for representing both partial and complete information on sets and tuples, and the introduction of a new ordering on interpretations that captures the intended semantics for nested sets, tuples and relations. Under appropriate stratification restrictions, it is shown that the unique minimal and supported model, if it exists, can be computed bottom-up, and therefore used as the intended semantics of the program. 1 Introduction In the past decade, there has been a lot of interest in nested relations, whose tuple components may be sets, tuples or even relations [2, 8, 11, 12, 14, 15]. The extended relational algebra and cal...

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