A relational algebra for user-defined periodicity

Author

Terenziani, Paolo

Author_Institution

Dipt. di Sci. e Technol., Univ. del Piemonte Orientale, Alessandria, Italy

fYear

1999

fDate

1999

Firstpage

494

Lastpage

500

Abstract

Calendars and periodicity play a fundamental role in many applications. Recently, some commercial databases started to support user-defined periodicity in the queries, providing high level languages to this purpose (e.g., TimeSeries in Oracle 8). On the other hand, existing relational data models do not support user-defined periodicity in the data, with few exceptions. We sketch a high level “symbolic” language for representing periodicity in a “human oriented” way, and propose a temporal relational model which supports user-defined “symbolic” periodicity in the validity time of tuples. We also define the temporal counterpart of the standard operators of the relational algebra, and introduce new temporal operators and functions. Finally, we sketch a symbolic implementation of the algebraic operators

Keywords

high level languages; relational algebra; relational databases; temporal databases; user interfaces; Oracle 8; TimeSeries; algebraic operators; commercial databases; high level languages; high level symbolic language; relational algebra; relational data models; standard operators; symbolic implementation; temporal counterpart; temporal operators; temporal relational model; tuples; user-defined periodicity; validity time; Algebra; Artificial intelligence; Banking; Calendars; Data models; High level languages; Multimedia databases; Process control; Process planning; Relational databases;

fLanguage

English

Publisher

ieee

Conference_Titel

Database and Expert Systems Applications, 1999. Proceedings. Tenth International Workshop on

Conference_Location

Florence

Print_ISBN

0-7695-0281-4

Type

conf

DOI

10.1109/DEXA.1999.795233

Filename

795233