Title
On database query languages for K-relations On database query languages for K-relations
Author
Faculty/Department
Faculty of Sciences. Mathematics and Computer Science
Publication type
article
Publication
,
Subject
Computer. Automation
Source (journal)
Journal of applied logic. - Place of publication unknown
Volume/pages
8(2010) :2 , p. 173-185
ISSN
1570-8683
Carrier
E
Target language
English (eng)
Full text (Publishers DOI)
Abstract
The relational model has recently been extended to so-called K-relations in which tuples are assigned a unique value in a semiring K. A query language, denoted by View the MathML source, similar to the classical positive relational algebra, allows for the querying of K-relations. In this paper, we define more expressive query languages for K-relations that extend View the MathML source with the difference and constant annotations operations on annotated tuples. The latter are natural extensions of the duplicate elimination operator of the relational algebra on bags. We investigate conditions on semirings under which these operations can be added to View the MathML source in a natural way, and establish basic properties of the resulting query languages. Moreover, we show how the provenance semiring of Green et al. can be extended to record provenance of data in the presence of difference and constant annotations. Finally, we investigate the completeness of View the MathML source and extensions thereof in the sense of Bancilhon and Paredaens.
E-info
https://repository.uantwerpen.be/docman/iruaauth/431139/e35e1325548.pdf