- From: Andy Seaborne <andy.seaborne@epimorphics.com>
- Date: Sun, 16 Dec 2012 21:41:55 +0000
- To: public-sparql-dev@w3.org
On 16/12/12 21:24, Bob DuCharme wrote:
> Imagine that I have ten million triples, and these are two of them:
>
> <http://w> rdfs:label "my literal" .
> <http://x> <http://y> <http://z> .
>
> I got the impression somewhere that this query
>
> SELECT ?s WHERE { ?s <http://y> <http://z> }
>
> would run faster than this one:
>
> SELECT ?s WHERE { ?s rdfs:label "my literal" }
>
> Is this true, and if so is it because URIs will always be indexed and
> literals won't necessarily be?
As far as I know, systems generally index literals - quite important for
keys.
Maybe there are many, many 'rdfs:label "my literal"' if it's not a key,
which might make a difference, as much because there are more results.
> Or is it all dependent on the
> implementation?
Yes.
Andy
Received on Sunday, 16 December 2012 21:42:26 UTC