Title

Time-Based Operators For Relational Algebra Query Languages

Keywords

boolean operators; calculus; historical databases; query languages; relational; relational algebra; snapshot databases

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. © 1993.

Publication Date

1-1-1993

Publication Title

Computer Languages

Volume

19

Issue

4

Number of Pages

261-276

Document Type

Article

Identifier

scopus

Personal Identifier

scopus

DOI Link

https://doi.org/10.1016/0096-0551(93)90011-O

Socpus ID

0345596166 (Scopus)

Source API URL

https://api.elsevier.com/content/abstract/scopus_id/0345596166

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