Fixed Block Compression Boosting in FM-Indexes

TL;DR

This paper introduces fixed block compression boosting, a new technique for FM-indexes that simplifies implementation, improves speed, and maintains strong theoretical and practical performance for compressed full-text self-indexes.

Contribution

The paper presents fixed block compression boosting, a novel method that simplifies and accelerates FM-index construction while preserving theoretical guarantees and practical efficiency.

Findings

Fixed block compression boosting is simpler and faster than previous methods.

The new technique maintains competitive compression ratios.

Implementation shows improved practical performance.

Abstract

A compressed full-text self-index occupies space close to that of the compressed text and simultaneously allows fast pattern matching and random access to the underlying text. Among the best compressed self-indexes, in theory and in practice, are several members of the FM-index family. In this paper, we describe new FM-index variants that combine nice theoretical properties, simple implementation and improved practical performance. Our main result is a new technique called fixed block compression boosting, which is a simpler and faster alternative to optimal compression boosting and implicit compression boosting used in previous FM-indexes.