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RE: Bookmarkable queries

From: Seaborne, Andy <andy.seaborne@hp.com>
Date: Thu, 13 May 2004 11:25:21 +0100
To: "'Rob Shearer'" <Rob.Shearer@networkinference.com>, "'RDF Data Access Working Group'" <public-rdf-dawg@w3.org>
Message-ID: <001001c438d4$98c499e0$0a01a8c0@atlas>



-------- Original Message --------
> From: public-rdf-dawg-request@w3.org <>
> Date: 11 May 2004 18:56
> 
> I think requirement 3.8 brings up major questions about just
> what we consider a "query". Does a "query" include a
> selection of the RDF source, or can the same query be
> executed against different sources? (The latter seems much
> more sensible to me...)

+1 : I don't see why the query should need to record the execution but I can
be persuaded by an example.  At the moment, I see it as a protocol matter
concerned more with selecting the service access point.

A "query" is one of Pat's 'familiar abuse of terminology'.  The term is used
for both a recipe (a sequence of symbols in the query language) for
executing requests and the request (execution instance).  A template can be
partially instantiated (the source set, still can be repeated used).  This
multiple use is widespread and so our documents will be read with both
meansings in mind - it isn't something a glossary can help with much.   C.f.
"program" - the file continaing the binary or the one-time execution.

Its this overloading that causes the "bookmarkable query" to be a bit
confusing. It isn't a term invented in this WG; it is a general web arch
thing.

> 
> It makes a lot of sense to make clear that a query should be
> encodable as text, and that requirement implicitly means that
> a query can be encoded *within* a URI, but that's a long way
> from saying that a query
> *is* a URI. The requirement as written conjures notions of
> new schemes and URLs and protocol dependence and all the rest.
> 
> At the very very least, I'd suggest changing "...a query as a
> URI." to "...a query within a URI."
> 
> I'm still not very happy with this requirement, because the
> whole URI issue just seems a side point. I don't think we
> need to standardize the format for a query URI in order to
> declare victory,

What I think this requirement really says is that the protocol must be able
to be used over HTTP GET as "bookmarkable".  Query is nromally a safe
operation and web caching also works. The requirement says very little about
the query language as x-www-form-urlencoded can be applied, if there is a
concrete syntax, it can be put in a URL.

The charter says "HTTP and/or SOAP-based protocol" so this  makes the HTTP
part a requirement.  

> and if we don't do that then I'm not sure
> we'll have grounds for deciding whether we've met the requirement.
> 
> I'd go back to the very simple "It must be possible to
> express a query as unicode text." (Better ideas than
> 'unicode'?) This actually subsumes the requirement that
> queries be able to be embedded in URIs, and yet I think we've
> already agreed on it, so it seems like a no-brainer.
Received on Thursday, 13 May 2004 06:29:30 GMT

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