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rdf 1.2 (rdf-star) meta queries very slow #1687
Description
Activity
Currently Oxigraph does not contain any good indexes for triple terms. So, queries like:
SELECT ?s ?p ?o WHERE { << ?s ex:p ex:o >> ?p ?o . }
is executed just like:
SELECT ?s ?p ?o WHERE { << ?s ?tp ?to >> ?p ?o . FILTER(?tp = ex:p && ?to = ex:o) }
We can optimize it by building indexes of triple terms like https://rubensworks.github.io/article-quoted-triples-index/
Reacted by Majid alDosariCurrently Oxigraph does not contain any good indexes for triple terms. So, queries like:
SELECT ?s ?p ?o WHERE {
<< ?s ex:p ex:o >> ?p ?o .
}
is executed just like:SELECT ?s ?p ?o WHERE {
<< ?s ?tp ?to >> ?p ?o .
FILTER(?tp = ex:p && ?to = ex:o)
}
We can optimize it by building indexes of triple terms like https://rubensworks.github.io/article-quoted-triples-index/What about querying the corresponding mapping quoted triples -> triples.?
I have a db with 'meta'/nested triples. As soon as I wrap a triple with
<< >>, the query becomes orders of magnitude slower whereas the corresponding 'normal' query is relatively instant.