On 29/01/15 11:05, Laurent Rucquoy wrote:
Hi Andy,
I've good response time now with the SPARQL request fixed by Milorad.
Nevertheless, I will focus on the TDB Optimizer soon and also upgrade Jena
to the last release (my current release is 2.10.1)
Thank you for your help.
Glad you've got it working.
2.11.2+ should effectively do what Milorad suggests - it should pick
image base:sopInstanceUID
"1.2.840.113564.10656621.201302121438403281.1003000225002"^^XMLS:string .
as the first triple pattern to evaluate.
The bug was that it would choose
?x a base:ImageAnnotation ;
and that is somewhat less selective.
Andy
Sincerely,
Laurent.
On Wed, Jan 28, 2015 at 7:44 PM, Andy Seaborne <[email protected]> wrote:
On 28/01/15 18:34, Milorad Tosic wrote:
Hi Laurent,
I would give a try to a different sequencing in the query. For example:
PREFIX base:<http://www.telemis.com/>PREFIX rdf: <
http://www.w3.org/1999/02/22-rdf-syntax-ns#>PREFIX XMLS: <
http://www.w3.org/2001/XMLSchema#>
SELECT ?x{ ?image base:sopInstanceUID "1.2.840.113564.10656621.
201302121438403281.1003000225002"^^XMLS:string . ?image a base:Image .
?seq ?p ?image . ?x base:images ?seq .
?x a base:ImageAnnotation ; base:deleted false .
}
Though, it may or may not help.
Regards,Milorad
From: Laurent Rucquoy <[email protected]>
To: [email protected]
Sent: Wednesday, January 28, 2015 6:13 PM
Subject: Very slow SPARQL query on TDB
Hello,
I have a Java application which implements an object model persisted
through JenaBean in my Jena TDB (see the attached image of the classes
diagram).
The request to retrieve an ImageAnnotation resource from the ID of a
linked Image is very slow.Here is a typical SPARQL query used (more than
40s to get the result):
PREFIX base:<http://www.telemis.com/>PREFIX rdf: <
http://www.w3.org/1999/02/22-rdf-syntax-ns#>PREFIX XMLS: <
http://www.w3.org/2001/XMLSchema#>
SELECT ?x{ ?x a base:ImageAnnotation ; base:deleted false ; base:images
?seq . ?seq ?p ?image . ?image a base:Image . ?image base:sopInstanceUID
"1.2.840.113564.10656621.201302121438403281.1003000225002"^^XMLS:string
.}
Can you help me to find what I'm doing wrong ?
Thank you in advance.
Sincerely,Laurent
Which version of TDB? 2.11.2 had possibly related fixes.
https://issues.apache.org/jira/browse/JENA-685
If you do take Milorad suggestion, also put in a "none.opt" file to stop
TDB reordering your improved order into a worse one.
http://jena.apache.org/documentation/tdb/optimizer.
html#choosing-the-optimizer-strategy
Andy
PS Attachments don't come through this list.
