A Representation-Independent Temporal Extension of ODMG's Object Query Language.
Marie-Christine Fauvet, Marlon Dumas, Pierre-Claude Scholl · 1999
TEMPOS is a set of models providing a framework for extending database systems with temporal functionalities. Based on this framework, an extension of the ODMG’s object database standard has been defined. This extension includes a hierarchy of abstract datatypes for managing temporal values and histories, as well as temporal extensions of ODMG’s object model, schema definition language and query language. This paper focuses on the latter, namely TEMPOQL. With respect to related proposals, the main originality of TEMPOQL is that it allows to manipulate histories regardless of their representations, by composition of functional constructs. Thereby, the abstraction principle of object-orientation is fulfilled, and the functional nature of OQL is enforced. In fact, TEMPOQL goes further in preserving OQL’s structure, by generalizing most standard OQL constructs to deal with histories. The overall proposal has been fully formalized both at the syntactical and the semantical level and implemented as a preprocessor.