Chapter 15


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.


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

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