DISTINCT in sparql definitions

• From: Vladimir Alexiev <vladimir.alexiev@ontotext.com>
• Date: Sat, 24 Oct 2015 04:01:58 +0300
• To: <public-data-shapes-wg@w3.org>
• Message-ID: <011c01d10df7$95484640$bfd8d2c0$@ontotext.com>

http://w3c.github.io/data-shapes/shacl/#PropertyScope has this SPARQL
DEFINITION:

SELECT DISTINCT ?this
WHERE {
	?this $predicate ?any .
}

(in total , DISTINCT occurs 7 times in the document)

A problem I see is that if the result of this query is very large, doing the
DISTINCT is expensive.
A more economic query would use 

   FILTER EXISTS {?this $predicate ?any}.

But afaik, you can't make a query out of a FILTER only...

Received on Saturday, 24 October 2015 01:02:17 UTC