Hello Marc-Alexandre,
The proper trick is
select distinct ?s
where {
?s rdf:type <http://biology.com/Protein> .
}
order by order by asc (bif:rnd(2000000000, ?s))
limit 100
but this is a costly thing because it should find all proteins during
the run. If you need random sampling on a regular basis, like choosing
approx. 1/10000 of database on a random-decimation style then it may be
convenient to extend the database with some "random-index" property, one
triple per subject, and filter by it.
Best Regards,
Ivan Mikhailov
OpenLink Software
http://virtuoso.openlinksw.com
