Title

Time-Based Operators For Relational Algebra Query Languages

Title - Alternative

Comput. Lang.

Keywords

Historical Databases; Query Languages; Snapshot Databases; Relational; Algebra; Relational; Calculus; Boolean Operators; Historical Databases; Computer Science, Software Engineering

Abstract

We present a new approach for historical relational algebra languages based upon generalized logic for Boolean and comparison operators and a temporal modification of the standard relational algebra operators. Historical versions of standard (snapshot) relational algebra operators based upon this generalized logic are presented. The temporal modification employs a logic that operates on sets of value/time-interval pairs and which can be applied to snapshot as well as historical databases. Our emphasis is that the generalized operators can be used to enrich existing historical query languages and to provide an easier and more natural time-based interface. Using the generalized operators, users can express their queries more naturally, succinctly and elegantly. Examples are presented which illustrate that the modified operators offer a good degree of flexibility in expressing different temporal requirements.

Publication Title

Computer Languages

Volume

19

Issue/Number

4

Publication Date

1-1-1993

Document Type

Article

Language

English

First Page

261

Last Page

276

WOS Identifier

WOS:A1993MP94500004

ISSN

0096-0551

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