Valid-time indeterminacy

Curtis E. Dyreson, Richard Thomas Snodgrass

Research output: Chapter in Book/Report/Conference proceedingConference contribution

28 Citations (Scopus)

Abstract

In valid-time indeterminacy, it is known that an event stored in a temporal database did in fact occur, but it is not known exactly when the event occurred. We present an extension of the tuple-timestamped temporal data model, called the possible chronons data model, to support valid-time indeterminacy. In the possible chronons data model, each event is represented with a set of possible chronons, delimiting when the event might have occurred, and a probability distribution over that set. We extend the TQuel query language with constructs that specify the user's credibility in the underlying valid-time data and the user's plausibility in the relationships among that data. We outline a formal tuple calculus semantics, and show that this semantics reduces to the determinate semantics on determinate data.

Original languageEnglish (US)
Title of host publicationProceedings - International Conference on Data Engineering
PublisherPubl by IEEE
Pages335-343
Number of pages9
ISBN (Print)0818635703
StatePublished - 1993
Event1993 IEEE 9th International Conference on Data Engineering - Vienna, Austria
Duration: Apr 19 1993Apr 23 1993

Other

Other1993 IEEE 9th International Conference on Data Engineering
CityVienna, Austria
Period4/19/934/23/93

Fingerprint

Data structures
Semantics
Query languages
Probability distributions

ASJC Scopus subject areas

  • Software
  • Engineering(all)
  • Engineering (miscellaneous)

Cite this

Dyreson, C. E., & Snodgrass, R. T. (1993). Valid-time indeterminacy. In Proceedings - International Conference on Data Engineering (pp. 335-343). Publ by IEEE.

Valid-time indeterminacy. / Dyreson, Curtis E.; Snodgrass, Richard Thomas.

Proceedings - International Conference on Data Engineering. Publ by IEEE, 1993. p. 335-343.

Research output: Chapter in Book/Report/Conference proceedingConference contribution

Dyreson, CE & Snodgrass, RT 1993, Valid-time indeterminacy. in Proceedings - International Conference on Data Engineering. Publ by IEEE, pp. 335-343, 1993 IEEE 9th International Conference on Data Engineering, Vienna, Austria, 4/19/93.
Dyreson CE, Snodgrass RT. Valid-time indeterminacy. In Proceedings - International Conference on Data Engineering. Publ by IEEE. 1993. p. 335-343
Dyreson, Curtis E. ; Snodgrass, Richard Thomas. / Valid-time indeterminacy. Proceedings - International Conference on Data Engineering. Publ by IEEE, 1993. pp. 335-343
@inproceedings{d9799aeaeff74b7a8861252a6b9fd179,
title = "Valid-time indeterminacy",
abstract = "In valid-time indeterminacy, it is known that an event stored in a temporal database did in fact occur, but it is not known exactly when the event occurred. We present an extension of the tuple-timestamped temporal data model, called the possible chronons data model, to support valid-time indeterminacy. In the possible chronons data model, each event is represented with a set of possible chronons, delimiting when the event might have occurred, and a probability distribution over that set. We extend the TQuel query language with constructs that specify the user's credibility in the underlying valid-time data and the user's plausibility in the relationships among that data. We outline a formal tuple calculus semantics, and show that this semantics reduces to the determinate semantics on determinate data.",
author = "Dyreson, {Curtis E.} and Snodgrass, {Richard Thomas}",
year = "1993",
language = "English (US)",
isbn = "0818635703",
pages = "335--343",
booktitle = "Proceedings - International Conference on Data Engineering",
publisher = "Publ by IEEE",

}

TY - GEN

T1 - Valid-time indeterminacy

AU - Dyreson, Curtis E.

AU - Snodgrass, Richard Thomas

PY - 1993

Y1 - 1993

N2 - In valid-time indeterminacy, it is known that an event stored in a temporal database did in fact occur, but it is not known exactly when the event occurred. We present an extension of the tuple-timestamped temporal data model, called the possible chronons data model, to support valid-time indeterminacy. In the possible chronons data model, each event is represented with a set of possible chronons, delimiting when the event might have occurred, and a probability distribution over that set. We extend the TQuel query language with constructs that specify the user's credibility in the underlying valid-time data and the user's plausibility in the relationships among that data. We outline a formal tuple calculus semantics, and show that this semantics reduces to the determinate semantics on determinate data.

AB - In valid-time indeterminacy, it is known that an event stored in a temporal database did in fact occur, but it is not known exactly when the event occurred. We present an extension of the tuple-timestamped temporal data model, called the possible chronons data model, to support valid-time indeterminacy. In the possible chronons data model, each event is represented with a set of possible chronons, delimiting when the event might have occurred, and a probability distribution over that set. We extend the TQuel query language with constructs that specify the user's credibility in the underlying valid-time data and the user's plausibility in the relationships among that data. We outline a formal tuple calculus semantics, and show that this semantics reduces to the determinate semantics on determinate data.

UR - http://www.scopus.com/inward/record.url?scp=0027316634&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=0027316634&partnerID=8YFLogxK

M3 - Conference contribution

SN - 0818635703

SP - 335

EP - 343

BT - Proceedings - International Conference on Data Engineering

PB - Publ by IEEE

ER -