W3C home > Mailing lists > Public > public-rdf-dawg@w3.org > October to December 2004

RE: SPARQL / Language spec ready for review [Howard's feedback]

From: Howard Katz <howardk@fatdog.com>
Date: Wed, 6 Oct 2004 08:57:38 -0700
To: "Eric Prud'hommeaux" <eric@w3.org>
Cc: "Dave Beckett" <dave.beckett@bristol.ac.uk>, "Dan Connolly" <connolly@w3.org>, "Andy Seaborne" <andy.seaborne@hp.com>, "Steve Harris" <S.W.Harris@ecs.soton.ac.uk>, "RDF Data Access Working Group" <public-rdf-dawg@w3.org>
Message-ID: <IKEOLCDFPBBPPAHGNKKOEEPOEPAA.howardk@fatdog.com>

Eric,
I'll be out of office for the next 24 hours. If you have any questions for
me I can answer them once I'm back. I've also got the SVG stuff under
control and will be able to update your PNG's at that point.
Howard

> -----Original Message-----
> From: public-rdf-dawg-request@w3.org
> [mailto:public-rdf-dawg-request@w3.org]On Behalf Of Eric Prud'hommeaux
> Sent: Wednesday, October 06, 2004 1:48 AM
> To: Howard Katz
> Cc: Dave Beckett; Dan Connolly; Andy Seaborne; Steve Harris; RDF Data
> Access Working Group
> Subject: Re: SPARQL / Language spec ready for review [Howard's feedback]
>
>
> I said I'd get to this today.
> I was wrong; had to play with the health inspections and immigration
> servivces all day. I only just finished Daves and Howards will take
> more attention than I have remaining. Should be back on in 8-10 hours.
>
> On Tue, Oct 05, 2004 at 07:12:27AM -0700, Howard Katz wrote:
> >
> > Hi Eric,
> >
> > This is done off a fairly quick read. I haven't tried to correlate my
> > feedback against Dave's or anyone else's comments. I'm mostly
> *not* doing a
> > lot of nit-picking against spelling errors and other typos at
> this point,
> > ie, this is a bit of a higher-level view. This was reviewed
> against 1.82.
> >
> > Hope it's useful,
> > Howard
> >
> > ------------------------
> > 1 Introduction
> >
> > If you're having sub-headings, as in "Document Outline" and "Document
> > Conventions", wouldn't it be more consistent to sub-number
> them, as in "1.1"
> > and "1.2"?
> >
> > ---------------------
> > 2 Making Simple Queries
> >
> > Why not use the same data and query example(s) in the initial pictorial
> > section and the following SPARQL syntax section? That way
> readers would get
> > a better feel for how one form translates into the other.
> >
> > -----------------------
> > last paragraph
> >
> > Where doesn't the "andy" come from? I don't see him in the graph above.
> >
> > ------------------------
> > 2.1 Writing a Simple Query
> >
> > Second paragraph, "The terms quoted ..."
> >
> > It's a fair distance from this sentence to the actual example
> below, and the
> > reader's eyes have to jump down to the example and then find
> their way all
> > the way back up again. Why not move this paragraph to either after the
> > "Data:" section or after the "Query:" section?
> >
> > ----------------------
> > 2.2 Triple Patterns
> >
> > I'm not sure if this requires a bit of reorg or not, but all
> the examples in
> > the preceding section have WHERE clauses containing triple
> patterns, but you
> > don't introduce the concept until here.
> >
> > More importantly, you never say what a triple pattern IS (ie, something
> > along the lines of "A template for describing an s-p-o triple, with
> > variables representing missing information to be filled in by
> the query" or
> > some such. That would be very useful for reader.
> >
> > At a minimum, I'd change sentence one from
> > "The building blocks of queries are triple patterns"
> > to
> > "The building blocks of queries are triple patterns, shown as
> the arguments
> > of the WHERE clauses in the three queries in the preceding section."
> >
> > ---------------------
> > As well, a brief sentence explaining that triple patterns are
> delimited by
> > parentheses ("(" and ")") would be useful.
> >
> > --------------------
> > Paragraph 2, "A triple pattern has either a graph label
> (URIRef, literal) or
> > a named variable in each of the subject, predicate and object
> positions."
> > Literals of course can only go in the object position. Is it ok
> to be this
> > imprecise? (I'm asking because I don't know and don't have a strong
> > opinion.)
> >
> > ----------------------
> > Definition: Triple Pattern
> >       "3" -> "three"
> >
> > ----------------------
> > 2.3 Graph Patterns
> > First paragraph, "This starts with conjunction - the 'and' of triple
> > patterns."
> >
> > It's not clear what "This ..." refers to. How about something
> like, "We'll
> > first look at conjunctions, which combine triple patterns using "and".
> >
> > -----------------------
> > Paragraph starting "There are is a bNode ..."
> >
> > 1) "are is" -> "is"
> >
> > 2) I don't understand the final clause in second sentence: ", nor to any
> > query."
> >
> > ------------------------
> > 2.4 Multiple Matches
> >
> > "The results of query" -> "The results of a query"
> >
> > ------------------------
> > 4.2 Multiple Optional Blocks
> >
> > Second paragraph, you introduce the concept of outer block.
> This hasn't been
> > previously discussed, so it's unclear what this refers to.
> Please define. As
> > well, you follow with a hypothetical, "If a new variable is
> introduced in an
> > optional block ...", a short "WHERE" snippet example showing
> this would be
> > very helpful.
> >
> > ------------------------
> > 4.3 Optional Matching
> >
> > Is there a new syntactic feature introduced here? If so, an
> example would be
> > helpful.
> > ------------------------
> > 5 Nested Patterns
> >
> > It would be useful to introduce this section with a brief explanation of
> > what nesting is. Ie, What is its purpose? Why is it useful?
> >
> > ------------------------
> > Final example in section:
> >
> > I don't see a correspondance between the arguments of the
> SELECT statement
> > and the headings in the result table. "mbox" would have to be
> SELECTed to be
> > output, wouldn't it, and what happened to "name"?
> >
> > ------------------------
> > 8 Choosing What to Query
> >
> > Third paragraph, "To execute a query, there needs to be the
> query and an RDF
> > graph."
> > Awkward. How about: "Query execution requires both a query and an RDF
> > graph."
> >
> > -------------------------
> > 9 Querying the Origin of Statements
> >
> > I realize you have a footnote on the first sentence saying the
> semantics are
> > undefined, but how about at least a very loose explanation of
> what a SOURCE
> > is in the paragraph itself, so the reader at least has a rough idea of
> > you're talking about? Maybe the footnote could be reworked and
> moved into
> > sentence number two? Ie, something like (I'm not claiming this is
> > technically accurate):
> >
> > " ... many RDF data stores augment this with the source of each
> statement.
> > Source is at present undefined, but is expected to refer in some
> > implementation-dependent way to the document of origin,
> possibly given by a
> > URL."
> >
> > or some such.
> >
> > ------------------------
> > 10 Summary of Query Patterns
> >
> > Does the bullet "disjunction" correspond to the "alternatives"
> mentioned in
> > "6 More Pattern Matching - Alternatives"?  I don't know the ultimate
> > dispostion of this section but suggest if it stays and is
> mentioned in this
> > list, that the terminology be made consistent.
> >
> > ------------------------
> > 11.2 Constructing an Output Graph
> >
> > I'm confused by the three boxed snippets. #3 is labelled
> "Example" -- are
> > the first two NOT examples as well? What distinguishes #3 from
> #1 and #2?
> >
> > Also, #3 has "PREFIX . . . CONSTRUCT". Are the ellipses part of
> the syntax??
> >
> > --------------------------
> > 11.4 Asking "yes" or "no" questions
> >    -> 11.4 Asking "Yes" or "No" Questions
> >
> > I'd also invert sentence #1 and tighten a bit:
> > "In order just to test whether a query pattern has a query
> solution or not,
> > the application can use the ASK form."
> >    ->
> > "Applications can use the ASK form to test whether a query pattern has a
> > solution or not."
> >
> > ------------------------------
> > 12.1 Standard Operations
> >
> > "The SPARQL language provides some of the operations on plain
> literals, XSD
> > integers and XSD floats taken from those in XQuery and XPath
> Functions and
> > Operators <http://www.w3.org/TR/xpath-functions/>."
> >
> > A bit awkward. Do you mean:
> >
> > "The SPARQL language provides a subset of the operations on
> plain literals,
> > XSD integers and XSD floats defined in XQuery and XPath Functions and
> > Operators <http://www.w3.org/TR/xpath-functions/>."
> >
> >
>
> --
> -eric
>
> office: +81.466.49.1170 W3C, Keio Research Institute at SFC,
>                         Shonan Fujisawa Campus, Keio University,
>                         5322 Endo, Fujisawa, Kanagawa 252-8520
>                         JAPAN
>         +1.617.258.5741 NE43-344, MIT, Cambridge, MA 02144 USA
> cell:   +1.857.222.5741 (does not work in Asia)
>
> (eric@w3.org)
> Feel free to forward this message to any list for any purpose other than
> email address distribution.
>
Received on Wednesday, 6 October 2004 15:55:58 GMT

This archive was generated by hypermail 2.3.1 : Tuesday, 26 March 2013 16:15:21 GMT