See also: IRC log
<trackbot> Date: 14 June 2011
<mhausenblas> RRSAgent make logs public
<mhausenblas> scribenick: ivan
<scribe> scribe: ivan
<MacTed> :-)
<mhausenblas> PROPOSAL: Accept the minutes of last meeting http://www.w3.org/2011/05/31-rdb2rdf-minutes.html
mhausenblas: any comment on the
minutes?
...
...
...
RESOLUTION: Accept the minutes of last meeting http://www.w3.org/2011/05/31-rdb2rdf-minutes.html
mhausenblas: who wants to start
dmcneil: i made a talk on r2rml
and spider
... fairly full room
... well received
... there were several questions, people followed along with
the ideas
... the pressing question was the question i posted on the
mailing list
... how to code a uri as a resource
... i got questions on the representation of the mapping
itself,
... some people pushed back on the verbosity of turtle
... one gentleman proposed a specific syntax for the
mapping
<mhausenblas> Michael: Enrico just send the following to the WG list: "Still stuck on the train with an horrible delay. I can't make it on time :-("
Ashok: what sort of syntax?
dmcneil: data representation,
concise to r2rml
... and translate that
<betehess> funny enough, ericP just posted a abstract model this morning
juansequeda: was good to see the
state of sw technologies
... i realized that people see that they need rdb to rdf
... eg people from golden sachs
... people from big it companies are waiting for us
mhausenblas: anyone else to report
<mhausenblas> Ivan: Cray has a big offering re iron
<ericP> dmcneil, here's a concrete syntax based on the example at the top of the r2rml spec: http://www.w3.org/2005/01/yacker/uploads/R2RML?lang=perl&markup=html#prod-R2RML-R2RML_Mapping
<ericP> (that'd different from the abstract syntax)
mhausenblas: any other reports
regarding semtech
... we should, in general, report when a wg member is at an
event, conference, etc
... use that to collect feedback
... getting to last call needs that
mhausenblas: should we go through
the action items or jump on the issues
... i know the enrico is delayed, but he may join us
later
... i would propose to start with issue 22
issue-22?
<trackbot> ISSUE-22 -- Support for database vendor specific SQL statements. -- open
<trackbot> http://www.w3.org/2001/sw/rdb2rdf/track/issues/22
Souri: i was going to make a comment on issue 18, I have started to update the document on the resolution of that one, should be done for next week
mhausenblas: so, issue 22, who
can help?
... dmcneil, you brought this up?
<cygri> Proposal: http://lists.w3.org/Archives/Public/public-rdb2rdf-wg/2011May/0179.html
action-133?
<trackbot> ACTION-133 -- Eric Prud'hommeaux to write proposal for issue-22 -- due 2011-06-07 -- OPEN
<trackbot> http://www.w3.org/2001/sw/rdb2rdf/track/actions/133
ericP: the prudent way of
handling mine is to see a resolution on whether we flag an
extended sql with anything
... we have some use to flag an extension with an
identifier
... the debate is whether we want to flag extensions in the
first place
mhausenblas: what is the issue you are referring to>
dmcneil: i think that is issue 22
ericP: the metaissue is that if
we have a syntax to distinguish between sql 2009 or an sql with
vendor specific
... if we have a flag for that, I have a syntax to do that
Ashok: a question
... eric, you were speaking of a flag like a binary one
... or are you speaking of an attribute with values
<mhausenblas> ignore cygri
<mhausenblas> ahm
ericP: the original proposal was
a flag, i proposed an attribute
... the dispute comes from cygri who feels it is not
necessary
<dmcneil> +q
ericP: the use cases that are
enabled with an attribute are not compelling to richard
... so i would like to see a decision on the basic question
Ashok: if we have an attribute,
that could be a string, what you end up choosing for, how you
actually act based on that, we do not specify
... ie, there is no harm for this
ericP: per richard it makes the spec more difficult to read
cygri: there are a number of issues with this; one is that it puts additional burden on the authors, 'cause they have to say which sql dialect they are using, and I think most of the authors have no idea
<Souri> agree with Richard about SQL writers not being aware of compatibility
cygri: most would have no
interest or the knowledge of what to use
... it is quite a complicated thing with different version of
sql
... the other issue is that i would expect most of the
implementation will be specific to a specific database
system
... they know what sql dialect they are connected to
... at that point the assumption is that if the author binds to
an oracle specific database, then it is a reasonable assumption
that the author will expect that the sql dialect is
oracle's
... the information is redundant, adds no value
dmcneil: i suggest that there is
a support to add a binary indicator
... and then the specific dialect may be decided later
cygri: it is the same problem, the author may not know that either
Ashok: eric, can you live with what richard recommended
<EFranconi> i'm trying
ericP: his recommendation is not to have a flag or an attribute
<Souri> if we include it, we could make it optional, more like a comment, just informative "works on: Oracle DB 11.2.*"
ericP: if we had a flag, i was interested for an attribute
<dmcneil> +q
ericP: if we do not have flag, I can live with that
dmcneil: we say in the spec that
we will use sql 2008
... but richard says, effectively, that the user can put
anything there
cygri: we define r2rml/sql2008
<MacTed> was this flag to be mandatory? it seems a strong value-add if known/included, so having it and making it optional seems a win...
cygri: if someone wants to use
r2rml with sql lite
... then they would be using r2rml/sql lite
... it is fairly clear what the behaviour would be
... but we do not necessarily say that
... and we can add something like 'you know what you would be
doing...'
dmcneil: in our implementation we
rely on that flag
... i can definitely say it is useful for us
MacTed: it seems problematic to
make mandatory, but if the information there it may be
useful
... so if it is optional, that is fine
cygri: i like to have this thing
as an optional
... i am not particularly opposed to it
... what is the process to get the concrete identifiers for the
dialects
... would we define those
mhausenblas: i would interpret
eric's action to draft this with the optional attribute
... eric, is that fine?
ericP: I can do that, i want to
do one for sql2008
... and the community can define to
mhausenblas: we can then resolve it next week
cygri: i am o.k. with that way of
making progress
... what is the chance that there will be some sort of a
standardization of these values
... to make things interoperable
... eric just said that he would propose one value
<Souri> I'd say cardinality should be 0-n (works for this, works for that, works for that too , ...)
MacTed: once one is define, the rest of use can throw in for others
mhausenblas: let eric start the process and let the others propose theirs
cygri: i am not sure how to
address every dialect
... anyway, we can talk about that when we have something on
the table
<Zakim> ericP, you wanted to say we define 1
<ericP> _:sMapping r:language <http://foo.example/tupleRelationalCaluculs> ; r:SQLQuery "Contacts : {company} | Contacts.name='Sue'" .
<mhausenblas> PROPOSAL: re ISSUE-22 the WG decides to have an OPTIONAL flag. this does not yet resolve ISSUE-22
+1
Souri: is that mean that it is compatible to XXX, yes, or no?
<dmcneil> +q
Ashok: the idea is that you have
an attribute and you can use that as you wish
... the spec does not spell out the details
dmcneil: the issue I see we say
sql queries for sql2008
... if you go to an r2rml process you expect that to run
... we would then water down
... it is implicit in there that there is vendor specific sql
and do not use that
<ericP> ivan: i read this as "if i use something other than 2008, then i might make it explicit with this flag"
cygri: I think it will be common to have implementations that will use a single or a small number of sql engines
<dmcneil> PROPOSAL: re ISSUE-22 the WG decides to have an OPTIONAL flag. this does not yet resolve ISSUE-22, if the flag is not used then all SQL is expected to be SQL-2008 compliant
cygri: these implementations will
accept queries in a particular dialect
... i may have sql lite
... that would make use of the flag
... i am opposed to have a flag that does not add any
value
... flags the individual queries is comletely wrong that do not
address a specific scenario
<Souri> +1 to Richard: we should make the common case less verbose (if SQL2008 => say it, if silent => it is NOT)
mhausenblas: one side, like dmcneil , who says that it is useful, another implementor says it does not really make sense
cygri: i am not disputing that it
can be useful
... i expect that it will be common to write the queries that
are not sql 2008
... and they do not want to flag
<Souri> if SQL2008 compatible: say it (if unspecified: may not be SQL2008 compatible)
cygri: what I said is that we do
not define that in our spec
... we would say that the flag is of a small scope
... what the proposal say that we define portability
... i am not o.k. having to flag for non sql all the time
<LeeF> I have no idea when I'm writing compliant SQL or not :)
cygri: it would be stupid to ask for this flag
<MacTed> flag is optional -- if it's present, it gives information about the SQL conformance/dialect. if it's not present, the information is unknown.
<MacTed> attribute likewise -- if it's present, it gives more detailed information than a flag.
Souri: my comment is that I agree
with richard, when I write a sql I am not really sure what
version it is
... i would like to get the common case
... if I do not know what it is compatible is,
... but if I know, then we have the option
... if i do not say anything, then it may or it may not be
compatible
<ericP> souri, a la { _:sMapping r:language _:dunno } ?
Souri: if I want to say then I can choose to use the attribute
<cygri> PROPOSAL: if attribute is present, we assume it's a specific dialect. if attribute is absent, we do not know what dialect it is. we only specify the behaviour of R2RML where the attribute says it's SQL-2008.
<MacTed> +1
<mhausenblas> PROPOSAL: Re ISSUE-22 the WG decides to introduce an OPTIONAL attribute. if attribute is present, we assume it's a specific dialect. if attribute is absent, we do not know what dialect it is. we only specify the behaviour of R2RML where the attribute says it's SQL-2008.
<cygri> +0.75
+1
<MacTed> it rounds up
<Souri> +0.75
<boris> +1
<betehess> +1
RESOLUTION: Re ISSUE-22 the WG decides to introduce an OPTIONAL attribute. if attribute is present, we assume it's a specific dialect. if attribute is absent, we do not know what dialect it is. we only specify the behaviour of R2RML where the attribute says it's SQL-2008.
issue-42?
<trackbot> ISSUE-42 -- How is the direct mapping suppose to handle NULL values wrt Information Preserving -- open
<trackbot> http://www.w3.org/2001/sw/rdb2rdf/track/issues/42
mhausenblas: as you all know we
have a deadline in september
... given that the group has spent about a month on issues 41
and 42
... i am inclined to resolve that asap
... i doubt that another month or even another year will solve
this
... my position that it is not solved yet, we cannot crack
it
... i would say we have two proposals on the table
... enrico's proposal is that the dm does not apply if there is
a null value in the database
<Zakim> ericP, you wanted to make a no change proposal
mhausenblas: my proposal is to reflect the schema in the proposal and omit triples with null
<EFranconi> in the latter case to omit triples with nulls, we shoudl add the note: add a note saying that in this case it is not known how to relate this interpretation to the semantics of the NULL of the rdb it comes from
<betehess> ericP, there *would* be a change: adding the table information, which isn't there yet
mhausenblas: if people agree with the september deadline, we resolve it today
juansequeda: the current spec
does not generate triples and the only thing to be added is the
table information
... and add some explanation to the text
ericP: the depth you can model
schema is arbitrary, one can add owl statements
... i can go deep into that
... or shallowest i can do, is to assume that the person
issuing the query knows the schema
<juansequeda> PROPOSAL: Add to the Direct Mapping spec the generating of the schema triples and also add a note stating that "it is not known how to relate this interpretation to the semantics of the NULL of the rdb it comes from"
ericP: the range is no change at all to deep curation of the data model in the relation model
<Souri> Schema generation (based on table and constraint definitions), non-generation of triples corr to NULL cells in table, and a note sounds good to me!
Ashok: there is one other possible action, that EFranconi proposed with all of its details
EFranconi: i do not disagree with
the proposal, but it is a message of failure of this
group
... what you say that the mapping does not say anything about
the semantics
<dmcneil> +q
EFranconi: a serious implementer would not take this seriously, it is a bad message
dmcneil: i agree with the conclusion of enrico, can we try to soften the message with 'unknown'
mhausenblas: i would suggest that we ask EFranconi to write a non rec track note that explains the problem space, and we could point to this non rec track note
<ericP> +1 to asking enrico to writing a note about the semantics of NULL
juansequeda: i have the suspicion that we can get the issue solved offline with EFranconi
<Seema> I agree that the note is too strong.
juansequeda: let us have this
proposal as now
... i am sure that the next week with enrico we can solve this
problem
<mhausenblas> PROPOSAL: Re ISSUE-42, the WG decides add to the Direct Mapping spec the generating of the schema triples and also add a note stating that "it is not known how to relate this interpretation to the semantics of the NULL of the rdb it comes from"
EFranconi: i do not think we can find the solution within a week, but i believe we can have a note that formulates the problem
mhausenblas: i hope that EFranconi would lead the effort to write this note
<Souri> +1 to the proposal (with a non-Rec track note)
<Zakim> ericP, you wanted to ask enrico for a concrete screw case with real-world example data
mhausenblas: it must be a note to not screw up planning
ericP: reading the issue of
EFranconi and I would like to see a real world example data
where our assumption of using non assertions breaks some
intuitive queries people would have
... ultimately we will need this
Ashok: that is a reasonable thing to have in a note
<Souri> +1
cygri: I try to capture this discussion better
<cygri> PROPOSAL: Re ISSUE-42, the WG decides add to the Direct Mapping spec the generating of rdfs:range (and possibly other) schema triples and also add a note to the Direct Mapping spec saying: "The DM does not generate triples for NULL values. For a detailed discussion of this issue, see the following document" which points to a separate working group note
cygri: ...
<dmcneil> +1
<ericP> +1
<Souri> +1
<Seema> +1 to Richard's wording
<betehess> +1
<MacTed> +1
+1
<EFranconi> abstain :-)
<privera> +1
<boris> +1
<juansequeda> +1
<LeeF> +1
RESOLUTION: Re ISSUE-42, the WG decides add to the Direct Mapping spec the generating of rdfs:range (and possibly other) schema triples and also add a note to the Direct Mapping spec saying: "The DM does not generate triples for NULL values. For a detailed discussion of this issue, see the following document" which points to a separate working group note
<ericP> for the record, i heard a +1 from ashok
<ericP> (verbal)
<Ashok> +1
mhausenblas: who would accept to take a lead this
EFranconi: for family reasons I
cannot take a leading role
... i am happy to contribute
juansequeda: i am talking on behalf of marcello, we can take the lead on that
action on juansequeda ask marcello whether he is happy be co-editor of the NULL Note
<trackbot> Sorry, couldn't find user - on
<juansequeda> jsequeda
<scribe> ACTION: member to juansequeda ask marcello whether he is happy be co-editor of the NULL Note [recorded in http://www.w3.org/2011/06/14-rdb2rdf-minutes.html#action01]
<trackbot> Sorry, bad ACTION syntax
action juansqueda ask marcello whether he is happy be co-editor of the NULL Note
<trackbot> Sorry, couldn't find user - juansqueda
<mhausenblas> ACTION: ivan to learn Zakimish [recorded in http://www.w3.org/2011/06/14-rdb2rdf-minutes.html#action02]
<trackbot> Sorry, amibiguous username (more than one match) - ivan
<trackbot> Try using a different identifier, such as family name or username (eg. ivan, imikhail)
<LeeF> ACTION: juan to ask marcello whether he is happy to be co-editor of the NULL Note [recorded in http://www.w3.org/2011/06/14-rdb2rdf-minutes.html#action03]
<trackbot> Created ACTION-134 - Ask marcello whether he is happy to be co-editor of the NULL Note [on Juan Sequeda - due 2011-06-21].
<ericP> actioncolon...
<mhausenblas> [adjourned]
<mhausenblas> 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) Succeeded: s/represntation/representation/ Succeeded: s/distinquish/distinguish/ Succeeded: s/shema/schema/ Found ScribeNick: ivan Found Scribe: ivan Inferring ScribeNick: ivan Default Present: +3539149aaaa, mhausenblas, Ivan, cygri_, +49.153.6.aabb, boris, privera, +1.781.273.aacc, MacTed, Ashok_Malhotra, +1.314.394.aadd, dmcneil, nunolopes, EricP, +1.603.897.aaee, Alexandre, +1.603.897.aaff, Seema, Souri, +575737aagg, juansequeda, LeeF, EFranconi Present: +3539149aaaa mhausenblas Ivan cygri_ +49.153.6.aabb boris privera +1.781.273.aacc MacTed Ashok_Malhotra +1.314.394.aadd dmcneil nunolopes EricP +1.603.897.aaee Alexandre +1.603.897.aaff Seema Souri +575737aagg juansequeda LeeF EFranconi Michael Boris Percy Ted Ashok David Juan Lee Enrico Regrets: Marcelo Agenda: http://lists.w3.org/Archives/Public/public-rdb2rdf-wg/2011Jun/0051.html Found Date: 14 Jun 2011 Guessing minutes URL: http://www.w3.org/2011/06/14-rdb2rdf-minutes.html People with action items: ivan juan member[End of scribe.perl diagnostic output]