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Re: Summary of open issues on query.

From: Steve Harris <steve.harris@garlik.com>
Date: Wed, 3 Feb 2010 12:15:22 +0000
Cc: SPARQL Working Group <public-rdf-dawg@w3.org>
Message-Id: <E4BE93E5-A083-4051-9E93-7F2F169339EC@garlik.com>
To: Andy Seaborne <andy.seaborne@talis.com>
On 3 Feb 2010, at 08:42, Andy Seaborne wrote:
...
> ISSUE-35
> Can aggregate functions take DISTINCT as an argument a la SELECT  
> COUNT(DISTINCT ?X)? 	
>
>  DONE  All built-in aggregates can take the word DISTINCT.
>  Custom ones do not; it's part of their definition,
>  i.e. different URIs for a DISTINCT and non DISTINCT form.

I thought that the custom ones could also take DISTINCT? My  
recollection may well be wrong though. Do you have a link to the  
strawpoll?

> ISSUE-41
> Does GROUP BY allow variables or expressions, and does it allow  
> mutiple expressions? 	
>  ??
>  (I hope it does - it's just key calculation)

Not quite, there are issues with what expressions can be projected.  
But agreed, I think it should be allowed.

We maybe should consider not allowing bare expressions to be projected  
from aggregated queries, i.e. requiring SAMPLE(), even when the same  
expression is GROUP BY'd.

- Steve

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Received on Wednesday, 3 February 2010 12:15:51 GMT

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