Solving equations in the relational algebra
Logic in Computer Science
2007-05-23 v2 Databases
Abstract
Enumerating all solutions of a relational algebra equation is a natural and powerful operation which, when added as a query language primitive to the nested relational algebra, yields a query language for nested relational databases, equivalent to the well-known powerset algebra. We study \emph{sparse} equations, which are equations with at most polynomially many solutions. We look at their complexity, and compare their expressive power with that of similar notions in the powerset algebra.
Cite
@article{arxiv.cs/0106034,
title = {Solving equations in the relational algebra},
author = {Joachim Biskup and Jan Paredaens and Thomas Schwentick and Jan Van den Bussche},
journal= {arXiv preprint arXiv:cs/0106034},
year = {2007}
}
Comments
Minor revision, accepted for publication in SIAM Journal on Computing