- From: Steve Harris <steve.harris@garlik.com>
- Date: Mon, 23 Nov 2009 18:08:43 +0000
- To: Andy Seaborne <andy.seaborne@talis.com>
- Cc: "public-rdf-dawg@w3.org Group" <public-rdf-dawg@w3.org>
On 23 Nov 2009, at 15:48, Andy Seaborne wrote:
> On 23/11/2009 14:50, Steve Harris wrote:
>>
>> Otherwise the pattern can be reordered without changing the
>> semantics,
>> as far as I understand it.
>
> It will depend on the implementation as to whether mixing quads
> +triples is the same. In a quad-centric implementation, sure, it's
> pattern flattening to quad-joins. But in others systems the triples
> and names graphs might be held differently resulting in different
> join characteristics within BGP/quad blocks and across them.
Good point, I was looking at it with quad-centric eyes.
> FILTER+joins (as in {}-joins) have scoping issues as per normal
> SPARQL.
Yup. Whereas if we just use whatever's in a template (i.e. BGP, maybe
GRAPH depending on syntax) then we wouldn't have that scoping issue.
Again, not really that bothered, just I'd prefer to exclude FILTER to
make it simpler.
- Steve
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Received on Monday, 23 November 2009 18:09:19 UTC