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1. Re: Why is my SPARQL query so slow when I use property restrictions?
alwu-Oracle Dec 12, 2014 10:57 PM (in response to user8897213)What is the hardware configuration? Please list the SGA, PGA, and your I/O subsystem. Are you using a VM?
Assume the hardware used is a balanced one, we can try the following and see if we can finish a reduced query in the designated time constraint.
e.g.
Run this first:
prefix ...
select ... {
?annulus a owl:Class ; rdfs:label ?annulusLabel ;
}
limit 100
Run this the second,
select ?annulus ?annulusLabel ?od ?wt {
?annulus a owl:Class ; rdfs:label ?annulusLabel ;
rdfs:subClassOf/rdfs:subClassOf rdl:X101001915
}
limit 100
Run this the third,
select ... {
?annulus a owl:Class ; rdfs:label ?annulusLabel ;
rdfs:subClassOf/rdfs:subClassOf rdl:X101001915 ;
rdfs:subClassOf [ a owl:Restriction ; owl:onProperty rdl:X101001912 ;
owl:hasValue ?od ] ;
}
Please record the SQL Monitor report and please also take a snapshot before and after running the query, and generate an AWR report. It is very useful to see the top waits. All these will be very helpful for Oracle to understand what is going on.
Thanks,
Zhe Wu -
2. Re: Why is my SPARQL query so slow when I use property restrictions?
user8897213 Jan 14, 2015 5:56 PM (in response to alwu-Oracle)Hi
alter session set optimizer_features_enable = '10.2.0.4';
This setting had a huge impact. On '12.1.0.2' the query never finish. With '10.2.0.4' setting it takes less than 5 seconds.
Per Øyvind