AllegroGraph RDFStore Version 4.0 LUBM Benchmark Results

The following describes the performance of retrieval and RDFS reasoning with the native AllegroGraph RDFS++ Reasoner and AllegroGraph Prolog using the LUBM benchmark, with on average 20 departments per university.

Dynamic Materialization

AllegroGraph's RDFS++ engine dynamically maintains the ontological entailments required for reasoning: it has no explicit materialization phase. Materialization is the pre-computation and storage of inferred triples so that future queries run more efficiently. The central problem with materialization is its maintenance: changes to the triple-store's ontology or facts usually change the set of inferred triples. In static materialization, any change in the store requires complete re-processing before new queries can run. AllegroGraph's dynamic materialization simplifies store maintenance and reduces the time required between data changes and querying.

AllegroGraph RDFStore 4.0 Benchmark for LUBM(8000)

The total number of files read in is 160,007 N-Triples files, a total of 155 GB. The total number of triples after running the queries is 1.106 billion. In the LUBM(8000) results below, AllegroGraph's dynamic materialization occurred as necessary to answer each query. Loading^* required a total of 1 hour and 48 seconds. The index time^# was 25 minutes and 2 seconds. The total query time was 12 minutes and 56 seconds. The table below shows the results of running the LUBM(8000) queries, the results are reported in seconds.

Lubm Query	# Triples	Time
Query 1	4	0.007
Query 2	2,528	247.064
Query 3	6	0.004
Query 4	34	0.025
Query 5	719	0.084
Query 6	83,557,706	390.057
Query 7	67	0.013
Query 8	7,790	0.134
Query 9	2,178,420	96.695
Query 10	4	0.008
Query 11	224	0.008
Query 12	15	0.031
Query 13	37,118	0.041
Query 14	63,400,587	32.978

Summary of LUBM(8000) Results

The platform for the test was 2 - 4 core Intel E5520 Processors at 2.26 GHz, with 48 GB RAM, running Fedora 10.

^* With 2 indices, in bulk mode.

^# UPI map building.

These queries were performed with full RDFS++ reasoning at query time. Because the LUBM benchmark was designed to test some aspects of OWL reasoning that (by design) are beyond the strength of the RDFS++ reasoner, we added the single triple:

ub:GraduateStudent rdfs:subClassOf ub:Student

The AllegroGraph RDFS++ Reasoner handles the following RDFS and OWL predicates correctly:

RDFS:

<http://www.w3.org/1999/02/22-rdf-syntax-ns#type>

<http://www.w3.org/2000/01/rdf-schema#subPropertyOf>

<http://www.w3.org/2000/01/rdf-schema#subClassOf>

<http://www.w3.org/2000/01/rdf-schema#range>

<http://www.w3.org/2000/01/rdf-schema#domain>

OWL:

<http://www.w3.org/2002/07/owl#sameAs>

<http://www.w3.org/2002/07/owl#inverseOf>

<http://www.w3.org/2002/07/owl#TransitiveProperty>

The AllegroGraph Reasoner does not handle full OWL restrictions. For that we recommend RacerPro.

AllegroGraph 3.3 benchmarks

You can find the AllegroGraph version 3.3 LUBM benchmark report here.