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Re: Basic Federated Query - some comments

From: Carlos Buil Aranda <cbuil@fi.upm.es>
Date: Wed, 27 Jul 2011 16:02:37 -0400
Message-ID: <CABdcz9E=p5s=Z_K_4TwSZMQrmetCrWJ5nLFb9WGP_hUNthZrAg@mail.gmail.com>
To: Andy Seaborne <andy.seaborne@epimorphics.com>
Cc: sparql Working Group <public-rdf-dawg@w3.org>
2011/7/26 Andy Seaborne <andy.seaborne@epimorphics.com>

> This message is a set of comments from reading the federated query
> document.  A separate message covers suggestions for SERVICE ?var.
>
> 0/ Delete xmlspec.xml which is not the document.
>
done

>
> 1/ There is no CVS log in the document.  Put in:
>
>    <div1 id="sec-cvsLog">
>      <head>CVS History (Last Call and after)</head>
>      <div2 id="sec-cvsLog-meat">
>        <pre>
>        </pre>
>      </div2>
>    </div1>
>
> and CVS log entries are added to the file.  This is useful fro last call
> and later when we must track changes carefully.
>
done

>
> 2/ Formatting:
>
> The data examples need to consistently use prefixes.  This will also
> shorten the data making it fix when printed.  Some examples are incomplete
> fragments -
>
> Some (e.g. first in 2.1), have got extra newlines
>
done

>
> 3/ Formatting:
>
> Keywords should be consistent.
>
> 'SILENT'
> SERVICE
> SERVICE keyword.
>
done

>
> Query uses <code></code> around keywords then CSS can take care of them.
>
> 4/ Formatting:
>
> sparql -> SPARQL (sec 2.3 maybe others)
>
done

>
> 5/ Formatting:
>
> URIs in text should not have <> -- it's not part of the URI. Use formatting
> to make them stand out e.g. <code>.
>
done

>
> 6/ formatting:
>
> Queries have "PREFIX foaf:" so use this in the query - not the full URI.
> (e.g. sec 2.2, end)
>
done

>
> By sections:
>
> Sec 2.1:
>
> "my local FOAF file at"
> We have services being "at" -- suggest s/ at//.
>
done

>
> Sec 2.2:
> "obtain their interests and the people who knows those people who have some
> interest"
> ==>
> "obtain their interests and the names of people they know"
>
> Formatting for nested SERVICE in OPTIONAL: I first read it as OPTIONAL
> after the first SERVICE, not nested.
>
done

>
>
> "This query requires the first SERVICE to be a federated query processor"
> ==>
> "This query requires the SPARQL query service at
> http://people.example.org/**sparql <http://people.example.org/sparql> to
> support basic federated query."
>
done

>
> Sec 2.3
>
> Stray ")" in first sentence.
>
> Substantive comments in the other message.
>
done

>
> Sec 2.5:
> "only people the that know"
> ==>
> "only people that know"
>
done

>
> It would be clearer to define result of SERVICE SILENT and an error as the
> solution sequence of one empty solution mapping rather than refer to "return
> all variables unbounded".  It is confusing about what is "the query" here.
>
I just changed the sentence, don't know if it is clearer now?

>
> Sec 2.6
>
> The example does not make the point.
>
> BINDINGS can be used when creating the query to send to a remote endpoint
> to limit the results. So BINDINGS does not appear in the application query
> that contains the SERVICE clause.
>
fixed in Axel's email

>
> Sec 3.1
>
> Split into two parts; one for translation from syntax to algebra, one for
> evaluation, to make it align to the structure of the query document (and
> SPARQL 1.0).
>
 done

>
> Put the examples in a subsection and not mix examples and definition.
>
done, new subsection after the agebra section

>
> Evaluation: of a Service Pattern:
>
> The evaluation does not cover SILENT for a fixed URI.  It call goes into
>
> Invocation( IRI, vars, P, Bindings(G, vars), SilentOp )
> but that is too informal.
>
how could it be more formal? any suggestion?

>
> "if IRI is a SPARQL service"
>
> How do I tell?
>
> Should be "if IRI", and then try the invocation, which will tell whether
> it's an endpoint or not.
>
done

Carlos

>
>        Andy
>
>
>
Received on Wednesday, 27 July 2011 20:03:23 GMT

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