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Please use this identifier to cite or link to this item: http://hdl.handle.net/1942/2990

Title: Temporal connectives versus explicit timestamps to query temporal databases
Authors: Abiteboul, S.
Herr, L.
VAN DEN BUSSCHE, Jan
Issue Date: 1999
Publisher: ACADEMIC PRESS INC
Citation: JOURNAL OF COMPUTER AND SYSTEM SCIENCES, 58(1). p. 54-68
Abstract: Temporal databases can be queried either by query languages working directly on a timestamp representation or by languages using an implicit access to time via temporal connectives. We study the differences in expressive power between these two approaches. First, we consider temporal and first-order logic. We show that future temporal logic is strictly less powerful than past-future temporal logic and also that there are queries expressible in first-order logic with explicit timestamps that are not expressible in extended temporal logic. Our proof technique is novel and based on communication complexity. Then, we consider extensions of first-order logic with fixpoints or while-loops. Again the explicit temporal version of these languages, using timestamps, is compared with an implicit one, using instructions for moving in time. We also compare the temporal versions of the fixpoint language with those of the while language. (C) 1999 Academic Press.
Notes: INRIA Rocquencourt, F-78153 Le Chesnay, France. Limburgs Univ Ctr, B-3590 Diepenbeek, Belgium.Abiteboul, S, INRIA Rocquencourt, Domaine de Voluceau,BP 105, F-78153 Le Chesnay, France.
URI: http://hdl.handle.net/1942/2990
DOI: 10.1006/jcss.1998.1598
ISI #: 000078783100005
ISSN: 0022-0000
Type: Journal Contribution
Validation: ecoom, 2000
Appears in Collections: Research publications

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