Hi Mitko,
The exact query is:
sparql select ?conflict ?dateBegin where { ?conflict a
<http://dbpedia.org/ontology/MilitaryConflict> ; ?p
<http://dbpedia.org/ontology/Event> . ?p rdfs:subPropertyOf rdf:type ;
<http://www.w3.org/2006/time#hasBeginning> ?dateBegin . }
EXPLAIN gives me this... do you need me to execute the explain() with
different parameters?
SQL> explain('sparql select ?conflict ?dateBegin where { ?conflict a
<http://dbpedia.org/ontology/MilitaryConflict> ; ?p
<http://dbpedia.org/ontology/Event> . ?p rdfs:subPropertyOf rdf:type ;
<http://www.w3.org/2006/time#hasBeginning> ?dateBegin . }');
REPORT
VARCHAR
_______________________________________________________________________________
{
Precode:
0: $20 "callret" := Call min_bnode_iri_id ()
5: $21 "callret" := Call __i2idn (<constant (#i868)>)
10: $22 "callret" := Call __i2idn (<constant (#i1)>)
15: $23 "callret" := Call __i2idn (<constant (#i1030009)>)
20: $24 "callret" := Call __i2idn (<constant (#i1021055)>)
25: $25 "callret" := Call __i2idn (<constant (#i1021199)>)
30: BReturn 0
from DB.DBA.RDF_QUAD by RDF_QUAD_POGS 0.21 rows
Key RDF_QUAD_POGS ASC ($27 "s-1-1-t2.S")
<col=551 P = $21 "callret"> , <col=552 O = $22 "callret">
row specs: <col=552 O LIKE <constant (T�)>> , <col=550 S < $20 "callret">
from DB.DBA.RDF_QUAD by RDF_QUAD_POGS 0.22 rows
Key RDF_QUAD_POGS ASC ($32 "s-1-1-t1.P", $31 "s-1-1-t1.S")
<col=551 P = $27 "s-1-1-t2.S"> , <col=552 O = $24 "callret">
row specs: <col=552 O LIKE <constant (T�)>>
from DB.DBA.RDF_QUAD by RDF_QUAD 0.16 rows
Key RDF_QUAD ASC ($36 "s-1-1-t0.S")
inlined <col=551 P = $22 "callret"> , <col=550 S = $31 "s-1-1-t1.S"> ,
<col=552 O = $25 "callret">
row specs: <col=552 O LIKE <constant (T�)>>
from DB.DBA.RDF_QUAD by RDF_QUAD 0.22 rows
Key RDF_QUAD ASC ($40 "s-1-1-t3.O")
inlined <col=551 P = $23 "callret"> , <col=550 S = $32 "s-1-1-t1.P">
row specs: <col=550 S < $20 "callret">
After code:
0: $43 "conflict" := Call __id2i ($36 "s-1-1-t0.S")
5: $44 "dateBegin" := Call __ro2sq ($40 "s-1-1-t3.O")
10: BReturn 0
Select ($43 "conflict", $44 "dateBegin", <$42 "<DB.DBA.RDF_QUAD
s-1-1-t3>" spec 5>, <$38 "<DB.DBA.RDF_QUAD s-1-1-t0>" spec 5>, <$34
"<DB.DBA.RDF_QUAD s-1-1-t1>" spec 5>, <$29 "<DB.DBA.RDF_QUAD s-1-1-t2>"
spec 5>)
}
STATUS after executing the query:
SQL> status();
REPORT
VARCHAR
_______________________________________________________________________________
OpenLink Virtuoso Server
Version 06.01.3127-pthreads for Linux as of Apr 19 2010
Started on: 2010/04/22 12:17 GMT+120
Database Status:
File size 6257901568, 763904 pages, 348771 free.
2621440 buffers, 38877 used, 1 dirty 0 wired down, repl age 0 0 w. io
0 w/crsr.
Disk Usage: 39070 reads avg 0 msec, 0% r 0% w last 81 s, 480 writes,
107 read ahead, batch = 164. Autocompact 0 in 0 out, 0% saved.
Gate: 488 2nd in reads, 0 gate write waits, 0 in while read 0 busy scrap.
Log = data/narysubproperty.trx, 4359 bytes
415060 pages have been changed since last backup (in checkpoint state)
Current backup timestamp: 0x0000-0x00-0x00
Last backup date: unknown
Clients: 4 connects, max 1 concurrent
RPC: 166 calls, -1 pending, 1 max until now, 0 queued, 270 burst reads
(162%), 1 second brk=21564690432
Checkpoint Remap 19 pages, 0 mapped back. 9 s atomic time.
DB master 763904 total 348771 free 19 remap 0 mapped back
temp 256 total 251 free
Lock Status: 0 deadlocks of which 0 2r1w, 0 waits,
Currently 1 threads running 0 threads waiting 0 threads in vdb.
Pending:
Client 1111:4: Account: dba, 1845 bytes in, 356618 bytes out, 1 stmts.
PID: 6351, OS: unix, Application: unknown, IP#: 127.0.0.1
Transaction status: PENDING, 1 threads.
Locks:
Running Statements:
Time (msec) Text
88 status()
Replication Status: Server db-ALX-DEV03.
db-ALX-DEV03 db-ALX-DEV03 0 OFF.
Hash indexes
43 Rows. -- 88 msec.
Am 22.04.2010 15:13, schrieb Mitko Iliev:
> Hi Martin,
>
> The default indexes should do, i don't see wrong plan or similar. So
> it's better to send us the execution plan so we can see how this
> query compiles on your site; to do this put the query in explain
> ('sparql ...query here ..') and execute via command line ISQL tool.
> When doing explain note that query should begin with SPARQL keyword.
> Also what are INI settings in Parameters section specifically
> NumberOfBuffers, how large is working set? Check the staistics with
> status () command again with ISQL tool.
>
> Best Regards, Mitko
>
> On Apr 22, 2010, at 12:45 PM, Martin Gerlach wrote:
>
>> Hi,
>>
>> The following SPARQL Query returns approx. 10000 results out of 35
>> million triples.
>>
>> select [distinct] ?conflict ?metadata [from
>> <http://example.com/mygraph>] where { ?conflict a
>> <http://dbpedia.org/ontology/MilitaryConflict> . ?conflict ?p
>> <http://dbpedia.org/ontology/Event> . ?p rdfs:subPropertyOf
>> rdf:type . ?p <http://example.com/mymetadata> ?metadata . }
>>
>> There are only 4 graphs including the Virtuoso default graphs and
>> all triples concerned are in <http://example.com/mygraph>. RDF_QUAD
>> has the following default indexes: GS, OP, POGS, SP.
>>
>> Now the given query seems to be really slow. With FROM clause it is
>> even slower than without. Using DISTINCT or not does not seem to
>> have much impact.
>>
>> Which indexes could help? I would think the query triple "?conflict
>> ?p <Event>" could be the cause for the delay - shouldn't an index
>> on just "O", "O,S", or "G,O,S" help? I tried each of the three
>> without much of an effect. Are there other tables which need to be
>> indexed in order to increase SPARQL perfomance?
>>
>> (Background: We have subclassed rdf:type dynamically for each ?s a
>> <Event> triple in order to annotate metadata, e.g. provenance,
>> source, time, ...)
>>
>> Any ideas?
>>
>> Thanks and cheers, Martin
>>
>>
>> --
>> ------------------------------------------------------------------------
>>
>>
Martin Gerlach
>> Research
>>
>> Neofonie Technologieentwicklung und Informationsmanagement GmbH
>> Robert-Koch-Platz 4 10115 Berlin fon: +49.30 24627 413 fax: +49.30
>> 24627 120 martin.gerl...@neofonie.de
>> <mailto:martin.gerl...@neofonie.de> http://www.neofonie.de
>>
>> Handelsregister Berlin-Charlottenburg: HRB 67460
>>
>> Geschaeftsfuehrung Helmut Hoffer von Ankershoffen (Sprecher der
>> Geschaeftsfuehrung) Nurhan Yildirim
>>
>> ------------------------------------------------------------------------
>>
>>
>>
Das WePad ist ein Tablet der neuesten Generation. Dem Nutzer bietet es
>> schnellen Zugang zum Internet, eine komplette Welt von sofort
>> nutzbaren Applikationen und einfachen Zugriff auf Bücher, Fotos
>> sowie auf Magazine und Tageszeitungen verschiedener Verlage, die
>> mit dem WeMagazine ePublishing Eco System realisiert wurden. Mehr
>> über das WePad auf www.wepad.mobi <http://www.wepad.mobi> oder auf
>> www.facebook.com/WePad <http://www.facebook.com/WePad>.
>>
>>
>> ------------------------------------------------------------------------------
>>
>>
_______________________________________________
>> Virtuoso-users mailing list Virtuoso-users@lists.sourceforge.net
>> https://lists.sourceforge.net/lists/listinfo/virtuoso-users
>
>
> -- Mitko Iliev Developer Virtuoso Team OpenLink Software
> http://www.openlinksw.com/virtuoso Cross Platform Web Services
> Middleware
>
>
> ------------------------------------------------------------------------------
>
>
_______________________________________________
> Virtuoso-users mailing list Virtuoso-users@lists.sourceforge.net
> https://lists.sourceforge.net/lists/listinfo/virtuoso-users
--
------------------------------------------------------------------------
Martin Gerlach
Research
Neofonie
Technologieentwicklung und
Informationsmanagement GmbH
Robert-Koch-Platz 4
10115 Berlin
fon: +49.30 24627 413
fax: +49.30 24627 120
martin.gerl...@neofonie.de <mailto:martin.gerl...@neofonie.de>
http://www.neofonie.de
Handelsregister
Berlin-Charlottenburg: HRB 67460
Geschaeftsfuehrung
Helmut Hoffer von Ankershoffen
(Sprecher der Geschaeftsfuehrung)
Nurhan Yildirim
------------------------------------------------------------------------
Das WePad ist ein Tablet der neuesten Generation. Dem Nutzer bietet es
schnellen Zugang zum Internet, eine komplette Welt von sofort nutzbaren
Applikationen und einfachen Zugriff auf Bücher, Fotos sowie auf Magazine
und Tageszeitungen verschiedener Verlage, die mit dem WeMagazine
ePublishing Eco System realisiert wurden. Mehr über das WePad auf
www.wepad.mobi <http://www.wepad.mobi> oder auf www.facebook.com/WePad
<http://www.facebook.com/WePad>.
