Modeling Temporal Semantics of Data

Grace Publications
Publication Type:
Journal Article
Asian Journal of Information Technology, 2003, 2 (1), pp. 25 - 36
Issue Date:
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Recently, many temporal query languages, such as TCAL and TQuel have been proposed for temporal databases. However, there are still some limitations such as the inadequacy on operating data with temporal elements and handling the semantics of time `NOW in these temporal query languages. After defining a new temporal relational algebra, in this paper we build a tuple calculus language based on gap-interval for temporal databases. This tuple calculus is designed to support time query, non-time query, and general temporal query. In particular, the semantics of time `NOW is well implemented in this language; and the first temporal-normalform of relations under the extended operators is closure in our temporal query language.
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