Hi there,
I've been experimenting with various reasoning profiles to get better
performance in my project, and I'm looking for guidance on how to push
materialization towards data creation time, rather than query time. I
believe this would suit my use-case: data mutations are infrequent (they do
happen), but queries need to be fast.
Some additional configuration context:
1. Loading some owl ontologies (~80k triples) into an in memory model
2. Bind it to a OWLMicro reasoner using bindSchema
3. Bind the reasoner to a TDB2 backed model
With just the ontologies loaded, even before I loaded any instance data,
this led to fairly slow queries (> 1 min). To confirm the issue was with
the inference layer, I serialized all the ground and inferred triples to a
second tdb2 backed dataset, with no inference layer, and my reference
queries were much faster (~100ms) and returned identical results.
Reading the docs, I gathered I could try to push materialization towards
data mutation time with a combination of forward reasoning and prepare. The
inference doc had this to say about the GenericRuleReasoner:
"When run in forward mode all rules are treated as forward even if they
were written in backward ("<-") syntax. This allows the same rule set to be
used in different modes to explore the performance tradeoffs."
However, I've run into a couple of issues:
1. If I setMode on the OWLMicroReasoner too FORWARD, I get the following
exception when I try to bind the reasoner to a graph:
org.apache.jena.reasoner.rulesys.BasicForwardRuleInfGraph cannot be cast to
org.apache.jena.reasoner.rulesys.FBRuleInfGraph
Due to the following line:(
https://github.com/apache/jena/blob/bfce1741cb12f9cf544235d32fba6598bc7341b5/jena-core/src/main/java/org/apache/jena/reasoner/rulesys/OWLMicroReasoner.java#L94
)
2. If I use a GenericRuleReasoner, loaded with OWLMicro rules set to
FORWARD mode, I can bind the reasoner, but then I get the following
execution error at query execution time:
Forward reasoner does not support hybrid rules - [ (?x owl:intersectionOf
?y) -> (?x rdf:type owl:Class) ]
Which I don't understand because that does not seem like a backward rule.
So to sum up, I have two questions:
1. What would be your recommended approach to pushing materialization to
data creation time
2. How would you create forward rules reasoner that implements OWLmicro, or
closest to
Thanks!
