- From: Seaborne, Andy <andy.seaborne@hp.com>
- Date: Mon, 25 Sep 2006 11:22:10 +0100
- To: RDF Data Access Working Group <public-rdf-dawg@w3.org>
We left open what to do about literals of the same value in DISTINCT results. I propose that term-distinct apply to literals, and not a form of value-distinct. SPARQL is defined for simple entailment anyway so for this entailment regime it would be term-distinct for literals. I propose that rq24 only talk about this. Some considerations: 1/ It's terms that are returned, not values, when encoded into the result set. But which term should be returned if two literals are value-distinct and not term-distinct? e.g. "1"^^xsd:integer "01"^^xsd:integer "1.0"^^xsd:decimal The SPARQL test suite is based on RDF graph equality [1] which uses term equality for literals. 2/ XPath/XQuery Functions&Operators [2] allows numeric type promotion - but XML schema datatypes does not and double/float/decimal have different value spaces. See [3]. "1.3"^^xsd:double != "1.3"^^decimal I've checked in a test [4] for literal distinctness. Andy [1] http://www.w3.org/TR/rdf-concepts/#section-graph-equality [2] http://www.w3.org/TR/xpath20/#promotion [3] http://www.w3.org/TR/swbp-xsch-datatypes/ [4] http://www.w3.org/2001/sw/DataAccess/tests/data/Distinct/
Received on Monday, 25 September 2006 10:22:32 UTC