Foundations Of Temporal Query Languages

Foundations Of Temporal Query Languages by David Toman, 1995.
In recent years, there have been numerous proposals that introduce time into standard relational systems. Unfortunately, most of the attempts have been based on ad-hoc extensions of existing database systems and query languages, e.g., TQUEL and TSQL. Such extensions often create many problems, when precise semantics needs to be developed, if one exists at all. In a recent survey by J. Chomicki, a clean way of defining temporal databases based on logic was proposed. This methodology views temporal databases as multi-sorted, finitely representable first-order structures. Query languages then became formulas in suitable logics over the vocabulary of such structures.