Skip Navigation

The Computer Journal 1994 37(7):588-597; doi:10.1093/comjnl/37.7.588
© 1994 by British Computer Society
This Article
Right arrow Full Text (PDF)
Right arrow Alert me when this article is cited
Right arrow Alert me if a correction is posted
Services
Right arrow Email this article to a friend
Right arrow Similar articles in this journal
Right arrow Similar articles in ISI Web of Science
Right arrow Alert me to new issues of the journal
Right arrow Add to My Personal Archive
Right arrow Download to citation manager
Right arrow Search for citing articles in:
ISI Web of Science (3)
Right arrowRequest Permissions
Google Scholar
Right arrow Articles by Knight, B.
Right arrow Articles by Ma, J.
Right arrow Search for Related Content
Social Bookmarking
Add to CiteULike   Add to Connotea   Add to Del.icio.us  
What's this?

A Temporal Database Model Supporting Relative and Absolute Time

B. Knight * and J. Ma *

School of Computing and Information Technology, University of Greenwich, Woolwich, London SE18 6PF, UK

This paper presents a temporal database model which allows the expression of relative temporal knowledge of data transaction and data validity times. The system is founded on an extension to Allen's axiomitization of time, given previously by the authors, which takes both intervals and points as primitive time elements. A general retrieval mechanism is presented for a database with a purely relative temporal knowledge which allows queries with temporal constraints in terms of any logical combination of Allen's temporal predicates. When absolute temporal duration knowledge is added, the consistency checking algorithm upon which the inference mechanism is based reduces to a linear programming problem. A class of databases, termed time-limited databases, is introduced as a practical solution to the problem of computational complexity of retrieval. This class allows absolute and relative time knowledge in a form which is suitable for many practical applications, where relative temporal information is only occasionally needed. The architecture of such a system is given, and it is shown that the efficient retrieval mechanisms for absolute-time-stamped databases may be adapted to time-limited databases.

Received November 1993. revised June 1994.

* School of Computing and Information Technology, University of Greenwich, Woolwich, London SE18 6PF, UK.


Add to CiteULike CiteULike   Add to Connotea Connotea   Add to Del.icio.us Del.icio.us    What's this?




Disclaimer:
Please note that abstracts for content published before 1996 were created through digital scanning and may therefore not exactly replicate the text of the original print issues. All efforts have been made to ensure accuracy, but the Publisher will not be held responsible for any remaining inaccuracies. If you require any further clarification, please contact our Customer Services Department.