Re: Unexpected DISTINCT?

>> In the absence of the DISTINCT or REDUCED keywords, the specification
>> gives a precise cardinality for the solutions that appear in the  
>> solution
>> sequence.
>
> Does this mean the DISTINCT part of the SPARQL specification is
> incorrect? It says:
> "The solution sequence with no DISTINCT or REDUCED modifier may
> include duplicate solutions"
>
> http://www.w3.org/TR/rdf-sparql-query/#modDistinct

It's probably more accurate to say "might" rather than "may", in that  
it depends on the data. If run against a certain dataset:

- DISTINCT is well-defined (no duplicates)
- neither DISTINCT nor REDUCED: well-defined (duplicates if the data  
includes duplicates)
- REDUCED: implementation-defined (might have duplicates).

-R

P.S., thank you for your response, Lee. I hadn't spotted REDUCED before.

Received on Tuesday, 27 March 2007 21:22:13 UTC