Definition
Viewing a temporal database as a collection of time-referenced (or timestamped) facts, a time reference in such a database is called relative if its value is dependent of the context. For example, this context can be the current time, now, or it can be another instant.
Key Points
The relationship between times can be qualitative (before, after, etc.) as well as quantitative (3 days before, 397 years after, etc.). If quantitative, the relationship is specified using a time span.
Examples: “Mary’s salary was raised yesterday,” “it happened sometime last week,” “it happened within 3 days of Easter, 2005” “the Jurassic is sometime after the Triassic,” and “the French revolution occurred 397 years after the discovery of America”.
The simplest example of a relative timestamp is a period that starts at a time in the past and extends to now, such as (2005, now). As the clock ticks, this period gets longer.
Cross-References
This is a preview of subscription content, log in via an institution to check access.
Access this chapter
Tax calculation will be finalised at checkout
Purchases are for personal use only
Recommended Reading
Jensen CS, Dyreson CE. A consensus glossary of temporal database concepts – February 1998 version. In: Etzion O, Jajodia S, Sripada S, editors. Temporal databases: research and practice. Berlin: Springer; 1998. p. 367–405. LNCS, vol. 1399.
Author information
Authors and Affiliations
Corresponding author
Editor information
Editors and Affiliations
Section Editor information
Rights and permissions
Copyright information
© 2018 Springer Science+Business Media, LLC, part of Springer Nature
About this entry
Cite this entry
Jensen, C.S., Snodgrass, R.T. (2018). Relative Time. In: Liu, L., Özsu, M.T. (eds) Encyclopedia of Database Systems. Springer, New York, NY. https://doi.org/10.1007/978-1-4614-8265-9_1408
Download citation
DOI: https://doi.org/10.1007/978-1-4614-8265-9_1408
Published:
Publisher Name: Springer, New York, NY
Print ISBN: 978-1-4614-8266-6
Online ISBN: 978-1-4614-8265-9
eBook Packages: Computer ScienceReference Module Computer Science and Engineering