Bottom-Up Evaluation of Datalog: Preliminary Report

TL;DR

This paper explores a bottom-up evaluation method for Datalog, introducing a 'Push' approach that reduces storage needs and minimizes runtime copying by performing extensive compile-time work.

Contribution

It presents a novel 'Push' evaluation method that optimizes Datalog execution by reducing intermediate storage and copying, with a focus on compile-time improvements.

Findings

The 'Push' method effectively reduces storage space.

Minimizes runtime copying of values.

Preliminary results show improved efficiency.

Abstract

Bottom-up evaluation of Datalog has been studied for a long time, and is standard material in textbooks. However, if one actually wants to develop a deductive database system, it turns out that there are many implementation options. For instance, the sequence in which rule instances are applied is not given. In this paper, we study a method that immediately uses a derived tuple to derive more tuples (called the Push method). In this way, storage space for intermediate results can be reduced. The main contribution of our method is the way in which we minimize the copying of values at runtime, and do much work already at compile-time.