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Time and Relational Theory, 2nd Edition
book

Time and Relational Theory, 2nd Edition

by C.J. Date, Hugh Darwen, Nikos Lorentzos
August 2014
Advanced content levelAdvanced
560 pages
15h 32m
English
Morgan Kaufmann
Content preview from Time and Relational Theory, 2nd Edition
Chapter 15

Queries

The various shorthands introduced in earlier chapters—especially Chapters 9 and 11—can help to reduce the complexity of temporal queries in general. Even with those shorthands, however, queries on a temporal database still have the potential to be quite complicated. This chapter considers a set of twelve sample queries and shows how those queries might be formulated on (a) a database consisting of current relvars only, (b) a database consisting of historical relvars only, and (c) a database consisting of a mixture of current and historical relvars. The chapter also discusses the possibility of using automatically defined views to simplify the formulation of such queries.

Keywords

“temporal” query; current relvar; historical relvar; ...

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Publisher Resources

ISBN: 9780128006313