Timestamp semantics and representation

Curtis E. Dyreson, Richard Thomas Snodgrass

Research output: Contribution to journalArticle

17 Scopus citations

Abstract

Many database management systems and operating systems provide support for time values. At the physical level time values are known as timestamps. A timestamp has a physical realization and a temporal interpretation. The physical realization is a pattern of bits while the temporal interpretation is the meaning of each bit pattern, that is, the time each pattern represents. All previous proposals defined timestamps in terms of seconds. However, as we show, there are at least seven definitions of this fundamental time unit. We propose a more precise temporal interpretation, the time-line clock, that constructs a time-line by using different well-defined clocks in different periods. We also propose timestamp formats for events, intervals and spans. These formats can represent all of time to the granularity of a second, and all of recorded history to a finer granularity of a microsecond. Our proposed formats were designed to be more space and time efficient than existing representations. We compare our formats with those used in common operating systems and database management systems.

Original languageEnglish (US)
Pages (from-to)143-166
Number of pages24
JournalInformation Systems
Volume18
Issue number3
DOIs
Publication statusPublished - 1993

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Keywords

  • clocks
  • Temporal databases
  • timestamp comparison

ASJC Scopus subject areas

  • Management Information Systems
  • Management of Technology and Innovation
  • Hardware and Architecture
  • Information Systems
  • Software

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