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Query against Joseki generating tons of SELECTs

784525Aug 12 2010 — edited Aug 20 2010
Hi, I'm running Joseki on Tomcat with the latest sdordf/sdordfclient jars. It's configured to hit my my Oracle setup (described in [this thread|http://forums.oracle.com/forums/thread.jspa?threadID=1106143&tstart=0]) and things mostly work. I can query it without problem most of the time, however running the query I've included below results in nearly 8000 SELECT statements being issued. Eventually the query returns successfully, this just seems unecessary.

The log file of a single session recording only the below query can be found here.

PREFIX rdfs: <http://www.w3.org/2000/01/rdf-schema#>
PREFIX rdf: <http://www.w3.org/1999/02/22-rdf-syntax-ns#>
PREFIX bsbm: <http://www4.wiwiss.fu-berlin.de/bizer/bsbm/v01/vocabulary/>

SELECT DISTINCT ?product ?productLabel
WHERE {
?product rdfs:label ?productLabel .
FILTER (<http://www4.wiwiss.fu-berlin.de/bizer/bsbm/v01/instances/dataFromProducer40/Product1828> != ?product)

<http://www4.wiwiss.fu-berlin.de/bizer/bsbm/v01/instances/dataFromProducer40/Product1828> bsbm:productFeature ?prodFeature .
?product bsbm:productFeature ?prodFeature .
<http://www4.wiwiss.fu-berlin.de/bizer/bsbm/v01/instances/dataFromProducer40/Product1828> bsbm:productPropertyNumeric1 ?origProperty1 .
?product bsbm:productPropertyNumeric1 ?simProperty1 .
FILTER (?simProperty1 < (?origProperty1 + 120) && ?simProperty1 > (?origProperty1 - 120))

<http://www4.wiwiss.fu-berlin.de/bizer/bsbm/v01/instances/dataFromProducer40/Product1828> bsbm:productPropertyNumeric2 ?origProperty2 .
?product bsbm:productPropertyNumeric2 ?simProperty2 .
FILTER (?simProperty2 < (?origProperty2 + 170) && ?simProperty2 > (?origProperty2 - 170))
}
ORDER BY ?productLabel
LIMIT 5

Comments

alwu-Oracle
Hi,

I loaded the data you mentioned in another thread and run the query using Jena API. I got one answer for the query without seeing any problem.
I also checked the output you uploaded. It is unclear why the original query failed. There was no exception printed out.

Could you please run the query using Jena API (instead of Joseki) and then send the stack trace?

Thanks,

Zhe Wu
784525
Zhe,
This query is returning, the problem is that it takes a remarkably long time. It's taking nearly 4.5 seconds when most finish in tens or hundreds of milliseconds. When I looked into the logs to investigate the possible problems, I discovered that this query is responsible for over 8000 SELECT statements being sent to the database.

Making this query via the Jena API causes the same behavior.

The code I'm using to submit the query along with the output that is printed to standard out are bundled here
alwu-Oracle
In my test, I only see one query. Please email me your contact information so that I can give you a call.

Thanks,

Zhe Wu
784525
Awesome, your offline help fixed it. Turns out I had the wrong sdordf.jar. The rest of the patch was applied properly, but I had missed that step apparently. This query is executing very quickly now, no flood of SELECTS. Thank you.

Edited by: nyoung on Aug 19, 2010 2:29 PM
alwu-Oracle
Cool. Is the other problem still there?

1115984

Zhe
784525
yes. still truncating results.
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Post Details

Locked on Sep 17 2010
Added on Aug 12 2010
#database-key-features, #rdf-graph-property-graph
6 comments
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