The Tsql2 Temporal Query Language

The TSQL2 Temporal Query Language

Temporal databases have been an active research topic for at least fifteen years. During this time, several dozen temporal query languages have been proposed. Many within the temporal database research community perceived that the time had come to consolidate approaches to temporal data models and calculus based query languages, to achieve a consensus query language and associated data model upon which future research can be based. While there were many query language proposals, with a diversity of language and modeling constructs, common themes kept resurfacing. However, the community was quite frag mented, with each research project being based on a particular and different set of assumptions and approaches. Often these assumptions were not germane to the research per se, but were made simply because the research required a data model or query language with certain characteristics, with the partic ular one chosen rather arbitrarily. It would be better in such circumstances for research projects to choose the same language. Unfortunately, no existing language had attracted a following large enough to become the one of choice. In April, 1992 Richard Snodgrass circulated a white paper that proposed that a temporal extension to SQL be produced by the research community. Shortly thereafter, the temporal database community organized the "ARPA/NSF In ternational Workshop on an Infrastructure for Temporal Databases," which was held in Arlington, TX, in June, 1993.

The Tsql2 Temporal Query Language

Recent Advances in Temporal Databases

The International Workshop on Temporal Databases held in Zurich, Switzerland, 17-18 September 1995 brought together researchers from academic and industrial institutions with database practitioners interested in keeping up with the state-of-the-art developments in the management of temporal data. A previous workshop in Arlington, Texas in June 1993 focused on the development of an infrastructure that would spur the development of commercial implementations of many of the generally agreed-upon features of temporal database management that have emerged from the temporal database research community over more than a decade of research. This ARP AlNSF-sponsored Arlington workshop saw the formation of the TSQL2 Language Design Committee, which led to the development of the recently completed TSQL2 Language Specification, and also created a "consensus" glossary of temporal database terminology and a test suite of temporal database queries. The Zurich workshop was conceived from the outset to be universal in scope, and international in participation. The Call for Papers sought to evoke the highest quality and most up-to-date temporal database research from around the world. Mindful of the important work accomplished by the previous workshop, the Call also specifically sought out research papers and panels that would comment and build upon the widely publicized results from Arlington. These proceedings contain the papers that were selected for presentation at the International Workshop, on Temporal Databases held in Zurich, Switzerland on 17-18 September 1995.