See also: IRC log
<trackbot> Date: 15 November 2011
<scribe> scribenick: mhausenblas
<scribe> Chair: Ashok
<Ashok> PROPOSAL: Accept the minutes of F2F meeting http://www.w3.org/2011/11/08-RDB2RDF-minutes.html
+1
RESOLUTION: Accept the minutes of F2F meeting http://www.w3.org/2011/11/08-RDB2RDF-minutes.html
Ashok:
http://www.w3.org/2001/sw/rdb2rdf/wiki/Last_Call#14_DM_and_R2RML_should_use_same_datatype_mapping
and
http://www.w3.org/2001/sw/rdb2rdf/wiki/Last_Call#15_DM:_PLUS_SIGN_character_in_value_of_a_pkey_column
are open
... is this it?
<Zakim> cygri, you wanted to say it doesn't apply to R2RML
<cygri> http://www.w3.org/2001/sw/rdb2rdf/r2rml/#dfn-iri-safe
Richard: Re LC comment 15, I
think this does not apply
... issue pointed out by Souri only is relevant for DM
Marcelo: Not looked at the LC comments yet
<Souri> handling in R2RML: "R2RML always performs percent-encoding when IRIs are generated from string templates. If IRIs need to be generated without percent-encoding, then rr:column should be used instead of rr:template, with an R2RML view that performs the string concatenation."
Ashok: Juan looked at the DM LC
comments and reported back to the WG that all but 14/15 have
been minor
... Eric, can you confirm?
Eric: Looking at it now
<ivan> http://lists.w3.org/Archives/Public/public-rdb2rdf-wg/2011Nov/0037.html
Ivan: this is the mail Juan sent earlier today
Eric: I'm looking at Juan's message now
<cygri> +1!
Ivan: Comment re Appendix A
... some small mistakes, confirmed to be fixed
Eric: Will send official response, yes
<cygri> +1 to Souri
Souri: R2RML also has the encoding issue (re LC comment 15)
Ashok: Eric and Marcelo - could you speak this issue from DM POV?
ericP: when creating the
identifiers, someone parsing them needs to understand the
escape characters, at least for boundaries
... most aggressive escaping would result in all of the Unicode
char in two or more UTFs
... this is an argument against using the form-enc from
HTML
... we take a more relaxed approach in the DM
<cygri> http://www.w3.org/2001/sw/rdb2rdf/r2rml/#dfn-iri-safe
Richard: this is what R2RML does
ATM
... so, anything that is not allowed in IRI or boundary char is
PER encoded
... fairly conservative encoding
... we don't encode Unicode char in general
... one difference between DM and R2RML is in the handling of
spaces
... there are two questions to it: 1) which chars to encode and
2) how to handle spaces
<Souri> space => '+' in DM vs. space => '%20' in R2RML
Richard: I argued for %20 as it
doesn't clash with +
... and also not intended as a general IRI escape
Eric: Counter use cases would be a 'cheesy' DM browser by leveraging an HTML form
Richard: Hmm ... how would you generate the URIs in this setup?
(Eric explains details via HTML form)
Richard: how exactly would this look like?
Eric: Guess there is no way getting around the '?', true
Richard: So, URI generation would be need
Michael: see also http://xkr.us/articles/javascript/encode-compare/
<MacTed> +1 for percent encoding in all cases, losing the "+" space substitution special case
Ashok: Can we resolve this
then?
... Eric, can you address LC comment 15 with this?
Michael: What's the resolution then?
Eric: Boundaries still unclear, spaces resolved, yes
Richard: IIRC we had an issue for this
<cygri> http://www.w3.org/2001/sw/rdb2rdf/track/issues/67
ISSUE-67?
<trackbot> ISSUE-67 -- Separation characters for reference IRIs and row IRIs -- closed
<trackbot> http://www.w3.org/2001/sw/rdb2rdf/track/issues/67
Richard: where is this addressed in the DM?
Eric: Will try to figure out now - we moved a bit around when addressing LC comments
<Ashok> Juan: What is the latest version of the DM document?
Richard: It was closed before LC,
and there is an info box in the DM - marked as open
question
... might make sense to re-open ISSUE-67, then?
<juansequeda> Ashok, it's http://www.w3.org/2001/sw/rdb2rdf/directMapping/. Looks like ericP updated it recently
<ericP> is that Overview.html or Overview.xml ?
<juansequeda> Overview.xml
<ericP> tx
<cygri> http://lists.w3.org/Archives/Public/public-rdb2rdf-wg/2011Nov/0035.html
<ericP> so we're going to have to mix that with the LC 'cause Overview.xml is out of date with the LC
<ericP> (i think)
Richard: Re LC comment 14
... I'm quite happy with the R2RML setting
... DM should normatively reference it
<cygri> http://www.w3.org/2001/sw/rdb2rdf/r2rml/#datatype-conversions
Richard: re-worded it, still same
behaviour
... makes it easier to reference it from DM
... and added a note that points to XML Schema 1.1
... addressed also limited precision issue
... I proposed a change in the DM in
http://lists.w3.org/Archives/Public/public-rdb2rdf-wg/2011Nov/0035.html
... DM would essentially sec. 10.2
Ashok: Would the DM Editors be ok with Richard's proposal?
<ericP> http://localhost/2001/sw/rdb2rdf/directMapping/#defn-literal_map
<ericP> http://www.w3.org/2001/sw/rdb2rdf/directMapping/#defn-literal_map
Eric: I was thinking about
something smaller, see URL above
... I agree that both should favour the canonical XML
Schema/SQL form
... if we use cast-to-str approach it might introduce backward
compatibility issues
... I'd prefer a simple, short table - would be a sub-set of
Richard's section
<Souri> Aside: Please confirm: what would be the generated IRI for EMAIL="John.Smith" in both R2RML (with rr:template "http://SCOTT.EMP#EMAIL-{EMAIL}") and in DM: http://SCOTT.EMP#EMAIL-John%2ESmith ?
Ashok: So, RDF uses the XML Schema form
Eric: yes, max. graph merges
Richard: re user defined types,
the spec can't define behaviour beyond very generic
things
... the 'try-to-cast-to-str' is more helpful than not saying
anything
... Giving some default handling for this helps interop
Eric: All user defined types things should be notes/implementer hints then?
Ashok: yes
Richard: R2RML does use note re user defined types already, yes
Ashok: seems we're in agreement
re user defined types
... what about canonical forms
Richard: Dunno difference between
SQL and XSD canonical form
... not convinced we need canonical forms at all
Ashok: Good to use canonical form for interop reasons
Richard: If your processor is
aware of datatypes, then no problem
... if not aware, then you'd get the identical string
representation, but only for equality
... not a huge advantage IMO
(Souri had to leave the telecon)
Richard: Still not clear what the XSD canonical forms are
Ashok: Wondering how we should advance then, here ...
Richard: Yes, it's not a huge advantage and it is expensive, sorta
Eric: Would help, for example, in SPARQL queries
Richard: IMO would be better if the underling RDF processor handles this rather than in our realm
Eric: I would like to see input normalisation as part of the spec/conformance
Richard: It's important to have a
deterministic output, yes
... we need to pick some kind of normalization
... but we would also get it by applying SQL canonical
form
... RDF also defines it, underlying software is expected to
implement it
Eric: I think that a large number SPARQL engines do only RDF entailment
Richard: True, but that's a
general problem - doesn't improve if we address it in
RDB2RDF
... makes our job harder where it really should be resolved on
a larger scale
Eric: In SPARQL there is a
distinction between FILTER and graph match
... we should ask what we expect what people do - should people
write it in a canonical form or not?
Richard: RDF doesn't say how to canonicalise, but during query time
Ted: Level of canonicalisation
varies a lot
... age, for example, does this mean years, etc?
... Too many special cases, we can't cater for
Ashok: we will carry on via
email
... this issue and translate tables are the two big ones
left
Michael: I'm on travel next week
Ashok: Will send out the agenda then
meeting adjourned
trackbot, end telecon
This is scribe.perl Revision: 1.136 of Date: 2011/05/12 12:01:43 Check for newer version at http://dev.w3.org/cvsweb/~checkout~/2002/scribe/ Guessing input format: RRSAgent_Text_Format (score 1.00) Found ScribeNick: mhausenblas Inferring Scribes: mhausenblas Default Present: Ivan, +3539149aaaa, mhausenblas, Ashok_Malhotra, cygri, +1.781.273.aabb, MacTed, nunolopes, +1.603.897.aacc, Souri, +1.314.394.aadd Present: Ivan +3539149aaaa mhausenblas Ashok_Malhotra cygri +1.781.273.aabb MacTed nunolopes +1.603.897.aacc Souri +1.314.394.aadd Michael Richard Ted Ashok Nuno David Marcelo Eric Seema Regrets: Boris Joerg Agenda: http://lists.w3.org/Archives/Public/public-rdb2rdf-wg/2011Nov/0040.html Found Date: 15 Nov 2011 Guessing minutes URL: http://www.w3.org/2011/11/15-RDB2RDF-minutes.html People with action items:[End of scribe.perl diagnostic output]