Re: Definition: Group in query editor's draft

On 22/09/10 06:59, Axel Polleres wrote:
> I have a small question about the Definition of "Group" in the query draft:
>
> "Group((),Ω) = { 1 ->  Ω }"
>
> ... shouldn't that be:
>
> "Group((),Ω) = { () ->  Ω }"
>
> i.e., what is the 1 supposed to mean?

The 1 is any key.  When the set of groups keys is the empty, which 
happnes for

SELECT (count(*) AS ?c) { ?s ?p ?o }

then there needs to be a key value for the group.

It could be said to be slightly more sense to be (1), not 1, as it's a 
list when then the key isn't empty.  The key just needs to be unique, 
and here, there is only one key so it's arbitrary.

	Andy

>
> Thanks for clarification,
> Axel
>
>
>
>

Received on Thursday, 23 September 2010 07:37:02 UTC