# Algorithms for Computing Inequality Joins

### Brahma Dathan, Stefan Trausan Matu

#### Abstract

Although the problem of joins has been known ever since the concept of relational databases was introduced, much of the research in that area has addressed the question of equijoins. In this paper, we look at the problem of inequality joins, which compares attributes using operators other than equality. We develop an algorithm for computing inequality joins on two relations with comparisons on two pairs of attributes and then extend the work to queries involving more than two comparisons. Our work also derives a lower bound for inequality joins on two relations and show that the two-comparisons algorithm is optimal.

Download#### Paper Citation

#### in Harvard Style

Dathan B. (2018). **Algorithms for Computing Inequality Joins**.In *Proceedings of the 7th International Conference on Data Science, Technology and Applications - Volume 1: DATA,* ISBN 978-989-758-318-6, pages 357-364. DOI: 10.5220/0006826803570364

#### in Bibtex Style

@conference{data18,

author={Brahma Dathan},

title={Algorithms for Computing Inequality Joins},

booktitle={Proceedings of the 7th International Conference on Data Science, Technology and Applications - Volume 1: DATA,},

year={2018},

pages={357-364},

publisher={SciTePress},

organization={INSTICC},

doi={10.5220/0006826803570364},

isbn={978-989-758-318-6},

}

#### in EndNote Style

TY - CONF

JO - Proceedings of the 7th International Conference on Data Science, Technology and Applications - Volume 1: DATA,

TI - Algorithms for Computing Inequality Joins

SN - 978-989-758-318-6

AU - Dathan B.

PY - 2018

SP - 357

EP - 364

DO - 10.5220/0006826803570364