Data Structures and Indexes

Abstract

A property graph is a complex structure requiring some care to be represented in the linear memory model¹ of computers. A memory representation for property graphs should be: (1) concise, i.e., represent a given graph with a small memory footprint; and (2) access-efficient, i.e., allow queries reading and writing as little data as possible to process a given query as quickly as possible on the given hardware architecture. Due to complexity of the PGM, there is no single data structure that can represent a property graph out of the box. Neither is there a representation that became a de facto standard for PGM. Usually, PGM representations combine multiple ideas and techniques to represent the various parts of a property graph. Some PGM representations differ drastically while other PGM representations differ only in a few aspects. To avoid redundancy and repetition, we structure the discussion of PGM representation into the following main aspects.