- From: Eric Prud'hommeaux <eric@w3.org>
- Date: Mon, 4 Oct 2004 09:05:02 -0400
- To: Dave Beckett <dave.beckett@bristol.ac.uk>
- Cc: andy.seaborne@hp.com, Howard Katz <howardk@fatdog.com>, Steve Harris <S.W.Harris@ecs.soton.ac.uk>, RDF Data Access Working Group <public-rdf-dawg@w3.org>
- Message-ID: <20041004130502.GB20897@w3.org>
some issues address in v1.79 On Mon, Oct 04, 2004 at 01:43:00PM +0100, Dave Beckett wrote: > > On Fri, 01 Oct 2004 17:28:35 +0100, "Seaborne, Andy" <andy.seaborne@hp.com> wrote: > > > Dave, Steve, Howard, > > > > The SPARQL language doc is ready for review in preparation for the telcon next > > Tuesday. Version v1.73 (or later) of: > > > > http://www.w3.org/2001/sw/DataAccess/rq23/ > > > > The intention is to publish this rough-and-ready version, complete with editors > > notes and comments. This will enable early review, showing where we are going > > and enable feedback from the more dedicated part of the community. There is > > still much to do in the document but we hope that this public working draft will > > indicate the directions we are taking even if the detail is still to be done. > > This is my initial set of comments, not complete but requested by Eric > as I had made it available to him as I drafted it. I may/will change my > opinion on some items after I have a readthrough when I get to the end > in a few more hours. > > Dave > > ---- > > General: > A thorough spellcheck is needed. > > Label all examples with Numbers, titles and add anchors. > Add all example queries, data files as separate files with URIs, link > to them. Add them to the test suite. > Add labels and anchors to all definitions. I haven't labeled any yet, but I copied the exampleOuter / exampleInner template from RDF Primer (and XQuery). There is a wad of disabled style associated with this. Andy, you can enable it to check it out -- it puts cool boxes around stuff. My macro grabbed the class from the inner <pre class="query|query todo?/> so it will be easy to make the outer boxes the right color. The RDF Primary sometimes has <div class="exampleOuter exampleInner"> and sometimes has <div class="exampleOuter"> <div class="c1"> <a id="example20" name="example20">Example 20: ... using <code>rdf:ID</code></a> </div> <div class="exampleInner"> I haven't worked to figure out the criteria for what needs an anchor and title. > Do not use underlining in the html style when it isn't a link. I'm not sure that's such a problem, but I change the name of the style from "underline" to "definedTerm" and changed the style to text-decoration : underline > In query results, some of the tables use ?x and some use bare x. > Some results use both! changing all the x (without regard to the actual variable name). > > Must Fix > > Consistency in use of individuals, sets of individuals > examples: > b in B used ok > T defined as a set and used as a member of that set, also defined > as tp. T in GP should be tp in GP. > > See also MUSTFIX below > > > Editorial comments - should fix > > > Title: SPARQL title does not mention protocol despite the 'P' in the > name. Best I could come with was "SPARQL Query - A Language for Querying RDF". > Later on the document suggests that protocol is a separate document. > > > Abstract > typo: "end users [missing words] to write" end users a way to write figured it shouldn't be off-puttingly formal > ToC > missing 4.3 added > 8 "Chosing What to Query" to match document capitals fixed > 12.2 ditto fixed 12.1 and 12.2 > Appendices labelled 1,2 actually A, B in doc now A, B =============== Going home before grocery store closes ================ cheers all > suggest removing see also, old material. It's not ToC. > > > 1 Introduction > > MUSTFIX: First sentence is wrong. > > The abstract syntax for RDF is not a "graph of nodes and arcs, often > expressed as triples". It is a set of triples called an RDF graph > formally defined in RDF semantics. It can be and is often described > as a graph of nodes and arcs but RDF is not nodes+arcs; that was an > RDF core decision closely argued. > > preference to graph "created dynamically" than "partly calculated on demand" > > > (un-numbered section) Document Outline > @@variables bound@@, @@bindings@@ can be linked to forward references > > "10 - Summary" doesn't match the style of the other paragraphs - no > explanation > > > 2 Making Simple Patterns > last sentence preference to "[Simple] patterns can be ..." > > [All graph pictures are unreadable when printed out, too dark. > Please re-compose on a light background or with much greater > contrast. black on gray doesn't work.] > > First example. I suggest not using _:1 _:2 since it's not legal in > N3, Turtle, N-Triples for blank node labels. I think a small edit > can make the first example executable, testable. > > I'd prefer full names for variables, for easy of readability > especially by non-native english speakers. So 'address' not 'addr' > and something else instead of 'addrm' > > > 2.1 > P2 > URIref expand to URI Reference for first use. Or use the > correct definition RDF URI Reference and link to it. > grammar - "XML. Qname" - delete the "." > Link to QName in XML sepcs. > datatype URIRef not URI > > Para "Because.." > here and later I see "URIs used" - check for consistency. I suggest > s/URI/URIref/ throughout > > N3/Turtle used without a reference, explanation. > > Spellings "intpretted" > > Para "Prefixes are..." > refering to an earlier query, but it doesn't say which of the three > previous it means. Suggest "same query as the previous one" > > > 2.2 Triple Examples > > P1 grammar s/for for/for/ > > P2 "bnodes" introduced without explanation. Should > be "blank node labels" [ref RDF docs] abbreviated to BNodes. > Doesn't say which positions that bnodes can be used in. > > > Definition RDF Term > > This implies that query variables are in the RDF data model since > they are along with U, L and BN. I suggest moving to another > block since V is not used till later. Maybe after/near Query Variable? > > Definition Query Variable > This defines an individual, all the RDF Term definitions are sets. > No letter is assigned to typically use it. > Suggest "A query variable qv". OR define the set Q. > > Defn. Triple Pattern > (spelling, grammar) > "A triple pattern is [a] triple of 3 slots subject, predicate, object .." > > MUSTFIX: "union Q" <- Q is never defined. Q presumably is a set of > Query Variables, in which case it is NOT Q, but a set of qv, or > define Q as a set of qv. > > This also defines 'ground' but that is not pulled out. Suggest > make it a separate 'Definition: Ground' block. > > > Definition Binding > suggest use B for variable, as they are used uppercase elswhere too. > Suggest give an example for the convention for writing down a binding > such as (f, "value") or ?f="value" or the tabular form > --------- > | ?f | > --------- > |"value"| > --------- > > Suggest give an example of a set of bindings such as > {?f="value", ?g="value2"} or the tabular form given later. > > Definition A substitution > suggest uppercase "Substitution" > Suggest not using B as a set of Bindings, but use SB or something > to differ from lowercase 'b' as an individual binding. > So this is a mapping S(set of b) > > How can a set of bindings define a substitution? > Suggest rewording > "A substitution S(B) on a set of bindings B maps a triple pattern ..." > suggest ... "by the corresponding [variable] value" > > Suggest putting a subst() example. > > > Definition Triple Pattern Matching > > MUSTFIX: I think there is a triple pattern/set of triple pattern > issue here unless you are solely comparing a graph with one triple. > > T was earlier defined as a set of triple pattern. So subst(T, b in > B) is not a substitution of a triple pattern, but of a set of > triple patterns (and a binding b in B). Could re-use tp in T which > was used in defining ground, and define subst(tp in T, b in B). > Then edit to match such as 'Triple Pattern tp matches ...' > > Use of entails, reference/link to RDF entailment. > > rdfs: prefix is used in the second data, this was not defined as > convention earlier. brql/sparql predefines rdf: but not rdfs:? > > > 2.3 Graph patterns > > P1 "There are bNodes" No, there is 1. > grammar: "not in the RDF graph [nor in] any query" > > Para "The next query.." but there is no query following. Confused. > Does that mean the query just given > Also grammar: > "one or more triple patterns which must all match for the graph > pattern to match." > - the 'all' and 'one or more' say different things. Is it all or 1? > > Maybe the definition following explains better, remove? > > > Definition: Graph pattern > > MUSTFIX: > "A conjunctive Graph Pattern GP is a set of triple patterns T." > > T was earlier defined as; > "let T be the set of triple patterns := A x A x A" > > So GP=T ? > > Not quite what was meant. GP is set of tp, where > tp is a Triple Pattern in T. > > Maybe triple pattern & triple patterns are too hard to use and make > nice sentences. Other suggestions ; triple pattern set. > > > Defn: Graph Pattern - Conjunction > > Defines "conjunctive Graph Pattern" not the title of the definition. > html - underlining doesn't match too > > > Defn: Graph pattern Matching > > Hmm, confused by "same" in: > "For a graph pattern to match, each triple pattern must match with > each query variable having the same value whereever it occurs." > > suggestions > > "For a graph pattern GP to match, all triple patterns tp in GP must > match with all query variables in all tp having the same value." > > This actually defines "Graph Pattern GP matches", not > "Graph Pattern Matching" > > Using T in GP which is a (set of triple patterns). Probably should > be tp in GP. > > MUSTFIX: > [[ > For all T in GP, subst(T, B) is a triple entailed by G. > subst(GP, B) is the graph pattern formed by subst(T, B) for all T in GP. > subst(GP, B) is a subgraph entailed by G if all triple patterns are grounded. > ]] > > This is reusing subst(t in TP, b in B) redefined over graphs > I suggest changing the name to graphsubst(GP, B) to distinguish it. > subst(T in TP, b in B) returns a triple pattern, may not be ground. > > Suggestion: > For all tp in GP, subst(tp, B) is a triple pattern entailed by G. > graphsubst(GP, B) is the graph pattern formed by subst(tp, B) for > all tp in GP. > graphsubst(GP, B) is a subgraph entailed by G if all triple > patterns are grounded. > > > 2.4 Multiple Matches > > "The results of query are all the ways a query can match the graph > being queried. Each match is one solution to the query and there > may be zero, one or multiple solutions to a query, depending on the > data." > > This uses "results", "solutions" and "matches", not in the same was > as previously defined. I suggest using results only, and use match > to mean graph matches, triple matches as used above: > > "2.4 Multiple results > > The results of query are all the ways a query can match the graph > being queried. Each result is one solution to the query and there > may be zero, one or multiple results to a query, depending on the > data." > > Aside: A query actually hasn't been defined yet. It's hinted that it > is something to do with graph pattern, but it hasn't been said so > far. i.e. no. > > Or if sticking with "matching" make it clearer what the difference > between a result and a solution is. > > Example query has commas between variables. Die. > > "When the query can match the data in more than one way, each > possibility is returned as a solution to the query. In addition, we > have more than one selected variable so each solution contains two > bindings of variables to values." > > so now there are results, query matches, solutions and possibilities :) > Query matching data hasn't been discussed. Graph patterns matching > Graphs has been, could be reused. Could also refer to sets of bindings. > > ... and now Query Solution is given. > > definition Query Solution: > "For conjucntion graph pattern GP, subst(GP, B), has no variables." > spelling: conjunction. > Also could add ".. and is a set of ground triple patterns" or possibly > define a Ground Graph Pattern. > > > 3 Constraining Values > > (Here the query uses selected variables without a comma) > > > Definition: Value Constraint > "A value constraint is a boolean expression that can be applied to > restrict graph pattern solutions." > For me that doesn't read as an expression that can refer to > non-boolean things as parts of the expression but which has a boolean > value. > > > Definition: Query Stage (partial definition). > > "Graph Pattern (set of triple patterns) + set of Value > Constraints. QS : GP x VR" > > + and x ? + doesn't mean addition here but...? You cannot > join/merge a set of triple patterns and a set of value constraints. > > spelling in comment: [[ operations [like] "source" ]] > > I prefer Query Block. > > > 4 Including Optional Values > > .... Review to continue from here ... -- -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 Monday, 4 October 2004 13:05:02 UTC