Come configurarlo

From STLab

• Configure the server by change the parameters in the file virtuoso.ini as shown in Installation. For more detatails see: http://docs.openlinksw.com/virtuoso/dbadm.html#VIRTINI
• To check the server status go in the SQL browser console of virtuoso and write the command status(). This will give the following table:

Database Status: File size 46297088000, 5651500 pages, 128378 free.
2000000 buffers, 1849750 used, 8 dirty 2 wired down, repl age 0 0 w. io 2 w/crsr.
Disk Usage: 10814301 reads avg 0 msec, 0% r 0% w last 146343 s, 425095 writes, 1951 read ahead, batch = 189. Autocompact 0 in 0 out, 0% saved.
Gate: 2099 2nd in reads, 0 gate write waits, 0 in while read 0 busy scrap.
Log = virtuoso.trx, 5139 bytes
4314066 pages have been changed since last backup (in checkpoint state)
Current backup timestamp: 0x0000-0x00-0x00
Last backup date: unknown
Clients: 168 connects, max 1 concurrent
RPC: 20801 calls, -168 pending, 1 max until now, 0 queued, 0 burst reads (0%), 0 second brk=9
Checkpoint Remap 1207851 pages, 0 mapped back. 661 s atomic time.
DB master 5651500 total 128378 free 1207851 remap 1 mapped back temp 710 total 704 free

In this table check the values of buffers and Checkpoint Remap to see if they exceed the inserted parameters' value. If thus go to virtuoso.ini and will change such values in NumberOfBuffers, MaxDirtyBuffers and MaxCheckPointRemap.

• Install Additional Packages:

  - rdf_mappers; 
  - Wiki; 
  - iSPARQL; 
  - dbpedia_dav.vad (this is in /tools/add_packages of wit)

• To verify the effectivenes of the setted parameters in the config.file, if the dbpedia dataset is in the server run the following banchmark queries:

PREFIX p: <http://dbpedia.org/property/>
SELECT ?film1 ?actor1 ?film2 ?actor2
FROM <dbpedia_infobox_properties_en> WHERE {
 ?film1 p:starring <http://dbpedia.org/resource/Kevin_Bacon> .
 ?film1 p:starring ?actor1 .
 ?film2 p:starring ?actor1 .
 ?film2 p:starring ?actor2 . }

PREFIX p: <http://dbpedia.org/property/>
SELECT ?artist ?artwork ?museum ?director FROM <dbpedia_infobox_properties_en> 
WHERE {
 ?artwork p:artist ?artist .
 ?artwork p:museum ?museum .
 ?museum p:director ?director }

PREFIX geo: <http://www.w3.org/2003/01/geo/wgs84_pos#>
PREFIX foaf: <http://xmlns.com/foaf/0.1/>
PREFIX xsd: <http://www.w3.org/2001/XMLSchema#>
SELECT ?s ?homepage FROM<dbpedia_geo_coordinates_en> FROM<dbpedia_homepages_en> WHERE {
  <http://dbpedia.org/resource/Teatro_Piccinni> geo:lat ?teatroLat .
  <http://dbpedia.org/resource/Teatro_Piccinni> geo:long ?teatroLong . 
  ?s geo:lat ?lat .
  ?s geo:long ?long .
  ?s foaf:homepage ?homepage .
  FILTER (
    ?lat        <=     ?teatroLat + 0.03190235436 &&
    ?long       >=     ?teatroLong - 0.08679199218 &&
    ?lat        >=     ?teatroLat - 0.03190235436 && 
    ?long       <=     ?teatroLong + 0.08679199218) }

• Other queries to test functionality in the case of DBPedia dataset:

select distinct ?type count(?type) from<dbpedia_article_categories_en> from <dbpedia_page_links_en> where {
      {<http://dbpedia.org/resource/Holy_Roman_Emperor> <http://purl.org/dc/terms/subject> ?type} UNION 
      {<http://dbpedia.org/resource/Holy_Roman_Emperor> <http://dbpedia.org/ontology/wikiPageWikiLink> ?link. 
      ?link <http://purl.org/dc/terms/subject> ?type}} 
 order by desc(count(?type)) limit 10

select distinct count(?l) ?s from <dbpedia_labels_it> from <dbpedia_page_links_it> where {
      {?s <http://www.w3.org/2000/01/rdf-schema#label> ?o FILTER regex(?o,"roma", "i")}. 
      ?s  <http://dbpedia.org/ontology/wikiPageWikiLink> ?l } 
order by DESC(count(?l)) limit 10

SELECT count(?t) ?t from <dbpedia_instance_types_en> from <dbpedia_page_links_en> where {  
      ?page <http://www.w3.org/1999/02/22-rdf-syntax-ns#type> <http://dbpedia.org/ontology/Actor>; 
       <http://dbpedia.org/ontology/wikiPageWikiLink> ?x.  
      ?x <http://www.w3.org/1999/02/22-rdf-syntax-ns#type> ?t }  
order by desc(count(?t)) limit 100

select distinct ?r ?x ?r1 ?y ?r2 ?z ?ar from <dbpedia_page_links_en> where 
 { <http://dbpedia.org/resource/Semantic_Web> ?r ?x . 
    ?x ?r1 ?y . 
    ?y ?r2 ?z . 
    ?z ?ar <http://dbpedia.org/resource/Mirror_neuron> }