On 17/12/2018 07:53, Vincent Ventresque wrote:
Are you sure that named graphs have better performance?
I'm not a specialist, and I'd like to know other users' opinion about
that question. I thinks it depends both on the structure of your data
and the queries you run.
My use case consisted in using a dataset with +/- 168 M triples,
including +/- 10 M titles (triples like ?s dcterms:title "some words"),
and running queries with FILTER(REGEX()) :
-- a query like this took a long time (1 min or more) :
SELECT * WHERE {
?edition dcterms:title ?title .
FILTER(REGEX(?title, $word, 'i')) .
?edition rdarelationships:expressionManifested ?expr .
?expression bnf-roles:r70 ?author .
?author foaf:familyName $name
$word is provided as a value?
$word looks like a variable to the optimizer so the FILTER is after the
whole of the BGP. With GRAPH, or using just the {} part, the scope of
the filter is reduced.
Add {}
SELECT * WHERE {
{
?edition dcterms:title ?title .
FILTER(REGEX(?title, $word, 'i')) .
}
?edition rdarelationships:expressionManifested ?expr .
?expression bnf-roles:r70 ?author .
?author foaf:familyName $name
}
}
-------------
-- whereas a query like this one takes about 1 sec :
SELECT * WHERE {
GRAPH <:titles> {
?edition dcterms:title ?title .
FILTER(REGEX(?title, $word, 'i'))
}
?edition rdarelationships:expressionManifested ?expr .
?expression bnf-roles:r70 ?author .
?author foaf:familyName $name
}
----------------
So, depending on your data, it might be more efficient to use named
graphs, e. g. :
SELECT ?rel (count (?rel) as ?co)
where {
GRAPH <:names> { ?object MKG:English_name 'Pyrilamine' } # <-- HERE
: named graph for names
?RelAttr owl:annotatedTarget ?object ;
owl:annotatedSource ?subject ;
owl:annotatedProperty ?rel ;
MKG:pyear '1967' .
}
group by ?rel
limit 10
-------------------------------
Then how to build named graphs?
There are several ways, here are 3 methods :
#1) when uploading files in Fuseki web interface, specify the graph URI
for the file
#2) use tdbloader : java -Xms4096m -Xmx4096m -cp ./fuseki-server.jar
tdb.tdbloader --graph=$namedGraph --tdb=$configFile $f
#3) use SPARQL INSERT + DELETE
#1 & #2 are fast, but all the triples of the file go into the same
graph, so maybe you have to have to modify your files first.
#3 is slower, but you don't have to modify your files. see my question
on StackOverflow :
https://stackoverflow.com/questions/48500404/sparql-offset-whithout-order-by-to-get-all-results-of-a-query
Le 07/12/2018 à 18:16, HYP a écrit :
OK. I explain my project in the following
The KG schema is composed of a set of semantic types like disease or
drugs, and a set of relations like treated_by(disease, drug).
Then each instance relation, like treated_by(disease_1, drug_1) has an
annotation property 'year' which means this triple occur in the 'year'.
My query has two steps. Firstly, query the related triples about some
drug, like Pyrilamine, and group them according to the relation types
and give a count. Secondly, query the related nodes in one relation type.
The first step query, like:
SELECT ?rel (count (?rel) as ?co)
where {
?object MKG:English_name 'Pyrilamine' .
?RelAttr owl:annotatedTarget ?object ;
owl:annotatedSource ?subject ;
owl:annotatedProperty ?rel ;
MKG:pyear '1967' .
}
group by ?rel
limit 10
On 12/8/2018 01:00，ajs6f<aj...@apache.org> wrote：
Let's slow down here a bit.
We can't give you any reasonable advice until you tell us _much_ more
about your work. What is the data like? What kinds of queries are you
doing? How are you running them? What do you expect to happen?
Please give us a great deal more context.
ajs6f
On Dec 7, 2018, at 11:45 AM, HYP <hyphy...@163.com> wrote:
I store the 1.4B triples in two steps. Firstly, I made 886 rdf files,
each of which contains 1615837 triples. Then, I upload them into TDB
using Fuseki.
This is a huge job. Are you sure that named graphs have better
performance?
Then how to build named graphs?
On 12/7/2018 23:48，Vincent Ventresque<vincent.ventres...@ens-lyon.fr>
wrote：
Do you mean -Xms = 64G ?
N.B. : with 1.4 B triples, you should have better performance using
named graphs.
Le 07/12/2018 à 16:37, 胡云苹 a écrit :
My memory is 64G and my setting is no upper limit.
On 12/7/2018 23:34，Vincent Ventresque<vincent.ventres...@ens-lyon.fr>
<mailto:vincent.ventres...@ens-lyon.fr> wrote：
Hello
How do you run fuseki? you can increase java memory limit with
java options :
java -jar -Xms4096m -Xmx4096m fuseki-server.jar
(where 4096m = 4 Go, but could be 8192m or more)
N.B. : I'm not a specialist, don't know if -Xms and -Xmx must be
the same
If I remember correctly the memory limit is 1.2 Go when you run
'./fuseki start' or './fuseki-server'
Vincent
Le 07/12/2018 à 16:23, 胡云苹 a écrit :
Dear jena,
I have built a graph with 1.4 billion triples and store it as a
data set in TDB through Fuseki upload system. Now, I try to make
some sparql search, the speed is very slow.
For example, when I make the sqarql in Fuseki in the following,
it takes 50 seconds. How can I improve the speed?
-
