# Using Compressed Suffix-Arrays for a Compact Representation of Temporal-Graphs

## TL;DR

This paper introduces TGCSA, a novel compact data structure based on the Compressed Suffix Array, for efficiently representing and querying large temporal graphs with overlapping contacts, outperforming existing methods in space and expressiveness.

## Contribution

The paper presents TGCSA, a new compact data structure that improves space efficiency and query capabilities for temporal graphs, especially with overlapping contacts, compared to state-of-the-art methods.

## Key findings

- TGCSA achieves a good space-time trade-off.
- TGCSA is efficient for complex temporal queries.
- TGCSA can represent overlapping contacts in temporal graphs.

## Abstract

Temporal graphs represent binary relationships that change along time. They can model the dynamism of, for example, social and communication networks. Temporal graphs are defined as sets of contacts that are edges tagged with the temporal intervals when they are active. This work explores the use of the Compressed Suffix Array (CSA), a well-known compact and self-indexed data structure in the area of text indexing, to represent large temporal graphs. The new structure, called Temporal Graph CSA (TGCSA), is experimentally compared with the most competitive compact data structures in the state-of-the-art, namely, EDGELOG and CET. The experimental results show that TGCSA obtains a good space-time trade-off. It uses a reasonable space and is efficient for solving complex temporal queries. Furthermore, TGCSA has wider expressive capabilities than EDGELOG and CET, because it is able to represent temporal graphs where contacts on an edge can temporally overlap.