query-febdda40082935b1373e3406aeeccdc2

rq turtle/ttl

Can we say anything about which items are included / excluded in a LIMIT 3000 type query 17:37, 5 July 2019 (UTC)) talk (TagishsimonConsider a query such as the one below, which returns 3,000 rows of a possible 12,000, by virtue of a LIMIT statement. Can we say anything about the way in which Blazegraph goes about selecting the 3k rows? There's no ORDER ... are we getting the lowest QIds, or a fairly random set of items? --

Use at

PREFIX wikibase: <http://wikiba.se/ontology#>
PREFIX wdt: <http://www.wikidata.org/prop/direct/>
PREFIX wd: <http://www.wikidata.org/entity/>
PREFIX schema: <http://schema.org/>
PREFIX bd: <http://www.bigdata.com/rdf#>
SELECT distinct ?item ?linkcount WHERE {
    ?item wdt:P31 wd:Q5 .
    ?item wdt:P21 wd:Q6581072 .
        ?item wikibase:sitelinks ?linkcount .
   ?item wdt:P106 ?prof .
VALUES ?prof {
wd:Q1056391#head_teacher
wd:Q37226#teacher
wd:Q974144#educator
wd:Q1569495#lecturer
wd:Q901222#tutor
wd:Q20794925#college_head
wd:Q121594#professor
wd:Q1622272#university_teacher
}
    FILTER NOT EXISTS { ?wfr schema:about ?item . ?wfr schema:isPartOf <https://en.wikipedia.org/>.}
    SERVICE wikibase:label {
        bd:serviceParam wikibase:language "en,fr,de,pl" .
    }
}
LIMIT 3000

Query found at

graph TD classDef projected fill:lightgreen; classDef literal fill:orange; classDef iri fill:yellow; v2("?item"):::projected v3("?linkcount"):::projected v5("?prof") v1("?wfr") c13(["en,fr,de,pl"]):::literal c7(["wd:Q6581072"]):::iri c3([https://en.wikipedia.org/]):::iri c11(["bd:serviceParam"]):::iri c5(["wd:Q5"]):::iri f0[["not "]] subgraph f0e0["Exists Clause"] e0v1 --"schema:about"--> e0v2 e0v1 --"schema:isPartOf"--> e0c3 e0v2("?item"):::projected e0v1("?wfr"):::projected e0c3([https://en.wikipedia.org/]):::iri end f0--EXISTS--> f0e0 f0 --> v1 f0 --> c1 f0 --> v2 f0 --> c2 f0 --> c3 v1 --"schema:about"--> v2 v1 --"schema:isPartOf"--> c3 v2 --"wdt:P31"--> c5 v2 --"wdt:P21"--> c7 v2 --"wikibase:sitelinks"--> v3 v2 --"wdt:P106"--> v5 bind1[/VALUES ?prof/] bind1-->v5 bind10(["wd:Q1056391"]) bind10 --> bind1 bind11(["wd:Q37226"]) bind11 --> bind1 bind12(["wd:Q974144"]) bind12 --> bind1 bind13(["wd:Q1569495"]) bind13 --> bind1 bind14(["wd:Q901222"]) bind14 --> bind1 bind15(["wd:Q20794925"]) bind15 --> bind1 bind16(["wd:Q121594"]) bind16 --> bind1 bind17(["wd:Q1622272"]) bind17 --> bind1 subgraph s1["http://wikiba.se/ontology#label"] style s1 stroke-width:4px; c11 --"wikibase:language"--> c13 end