IRC log of RDB2RDF on 2011-12-13

Timestamps are in UTC.

16:53:31 [RRSAgent]
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16:53:31 [RRSAgent]
logging to
16:53:39 [Ashok]
chair: Ashok
16:53:48 [Ashok]
meeting: RDB2RDF
16:54:16 [Ashok]
Regrets: Michael, Ivan, Joerg, Boris
17:01:52 [juansequeda]
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17:02:18 [dmcneil]
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17:03:36 [nunolopes]
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17:04:01 [nunolopes]
Zakim, who is here?
17:04:01 [Zakim]
sorry, nunolopes, I don't know what conference this is
17:04:03 [Zakim]
On IRC I see nunolopes, dmcneil, juansequeda, RRSAgent, Zakim, Ashok, LeeF, MacTed, iv_an_ru, betehess, trackbot, ericP
17:04:04 [cygri]
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17:04:21 [cygri]
zakim, i'm with nunolopes
17:04:21 [Zakim]
sorry, cygri, I do not recognize a party named 'nunolopes'
17:04:44 [cygri]
zakim, what's the code?
17:04:44 [Zakim]
sorry, cygri, I don't know what conference this is
17:04:52 [cygri]
zakim, this is RDB2RDF
17:04:52 [Zakim]
ok, cygri; that matches SW_RDB2RDF()12:00PM
17:04:58 [cygri]
zakim, what's the code?
17:04:58 [Zakim]
the conference code is 7322733 (tel:+1.617.761.6200, cygri
17:05:05 [cygri]
zakim, i'm with nunolopes
17:05:05 [Zakim]
sorry, cygri, I do not recognize a party named 'nunolopes'
17:05:19 [cygri]
zakim, who is here?
17:05:19 [Zakim]
On the phone I see Ashok_Malhotra, dmcneil, juansequeda, cygri
17:05:20 [Zakim]
On IRC I see cygri, nunolopes, dmcneil, juansequeda, RRSAgent, Zakim, Ashok, LeeF, MacTed, iv_an_ru, betehess, trackbot, ericP
17:05:29 [cygri]
zakim, nunolopes is with me
17:05:29 [Zakim]
+nunolopes; got it
17:05:43 [Zakim]
17:06:07 [Ashok]
present: Ashok, David, Juan, Nuno, Richard, Souri
17:06:09 [Souri]
Souri has joined #rdb2rdf
17:06:13 [Seema]
Seema has joined #rdb2rdf
17:06:15 [Zakim]
17:06:25 [MacTed]
Zakim, OpenLink_Software is temporarily me
17:06:25 [Zakim]
+MacTed; got it
17:06:27 [dmcneil]
i can scribe
17:06:27 [MacTed]
Zakim, mute me
17:06:27 [Zakim]
MacTed should now be muted
17:06:34 [Ashok]
present+: Ted, Seema
17:07:09 [Ashok]
scribenick: dmcneil
17:07:22 [Zakim]
17:07:40 [Ashok]
Topic: Accept the minutes of last meeting
17:08:45 [Ashok]
Topic: Accept minutes of Dec 6
17:09:33 [ericP]
Zakim, please dial ericP-office
17:09:33 [Zakim]
ok, ericP; the call is being made
17:09:34 [MacTed]
Dec 6 was cancelled
17:09:35 [Zakim]
17:10:11 [Ashok]
Sorry, minutes for Nov 29 ...
17:10:29 [dmcneil]
RESOLVED: Accept the minutes of last meeting
17:11:10 [dmcneil]
david requested that we add an agenda item to talk about process
17:11:48 [dmcneil]
w3c process discussion
17:11:57 [ericP]
topic: w3c process discussion
17:12:22 [Ashok]
W3C Process document:
17:12:41 [dmcneil]
per eric the process has evolved a bit since the link above
17:13:01 [cygri]
see also ivan's mail:
17:13:19 [dmcneil]
we are currently working on last call comments
17:13:33 [dmcneil]
next stage is to go to a candidate recommendation where we ask if people have implemented the spec
17:13:37 [dmcneil]
we have not started this yet
17:13:58 [dmcneil]
it requires 1) defining test cases and 2) talk about what implementors need to report re: test cases
17:14:15 [dmcneil]
once we have at least two implementation then we can request that it become a recommendation
17:14:26 [dmcneil]
this would be version 1.0 of the new specs
17:14:44 [dmcneil]
possibly we would go on to define 1.1, etc.
17:15:20 [dmcneil]
it is quite reasonable to omit features from 1.0 in the interest of getting this to a recomendation and allow us to think about features for 1.1
17:15:31 [dmcneil]
anything to add eric?
17:15:56 [dmcneil]
eric: there is also a PR, proposed recommendation
17:16:22 [dmcneil]
there will also be implementation reports from implementors
17:17:16 [dmcneil]
probably we would wait for more than two implementations
17:17:46 [Ashok]
present+: Eric
17:17:58 [dmcneil]
working group would track what comments we are not accepting
17:18:10 [dmcneil]
once you exit CR, it is a short path to "rec"
17:18:37 [dmcneil]
we also have to tell the world how to run our tests
17:18:38 [cygri]
17:19:05 [dmcneil]
cygri: does the test suite need to be finalized to go to CR?
17:19:26 [dmcneil]
ericP: no, we get to define the details of what the exit criteria are
17:19:37 [cygri]
ack me
17:19:47 [dmcneil]
ashok: how formal is the process?
17:20:23 [dmcneil]
ericP: the level of formality varies, it is function of the test suite
17:21:30 [dmcneil]
17:21:50 [Zakim]
17:21:55 [dmcneil]
cygri: so there is the CR stage and then the PR, right?
17:22:11 [Zakim]
17:22:17 [dmcneil]
ericP: CR to PR is hard, have to prove implementations
17:22:23 [dmcneil]
PR to rec is typically easier
17:22:32 [dmcneil]
cygri: question is: how to get to CR
17:22:48 [dmcneil]
we know how we want to do the test suite and it is starting to take shape, collecting more test cases
17:22:56 [dmcneil]
is that sufficient to get to CR, or is more needed?
17:23:19 [dmcneil]
ericP: technically we could probably go to CR immediately, but it is better to have a story more straight before that
17:23:28 [dmcneil]
because going to CR generates a buzz of activity from the community
17:23:44 [dmcneil]
we also need to define what interoperablity means
17:24:13 [dmcneil]
cygri: we also need to address all last call comments to get to CR
17:26:12 [dmcneil]
david: where should I look to see changes since last call?
17:26:25 [dmcneil]
ericP: at each stage there will be a new doc produced and editors provide a diff
17:26:26 [cygri]
Editor's Draft:
17:27:05 [dmcneil]
cygri: end of editors draft list CSV commits with comments
17:27:23 [dmcneil]
17:27:36 [cygri]
17:27:40 [dmcneil]
i would hope that all my changes were in response to last call comments, well reasoned, etc
17:28:08 [dmcneil]
cygri: that last link is a list of relevant changes, things that would affect implementors working on the spec
17:28:26 [dmcneil]
those resources for R2RML should give a pretty good picture of what has changed,
17:28:35 [dmcneil]
plus there is the issues list where resolutions should be recorded
17:29:26 [ericP]
dmcneil: i'd like a text diff; perhaps i have to create that myself
17:29:55 [ericP]
... is the editor's draft completely at the whim of the editors?
17:30:44 [ericP]
cygri: i believe my edits respond to WG decisions
17:32:16 [dmcneil]
ashok: the editors should only write things agreed by WG
17:33:31 [dmcneil]
ericP: technically the W3C obligation is only at publication time
17:33:36 [dmcneil]
otherwise it is up to the team to agree
17:33:46 [ericP]
-> CVS "Blame"
17:34:12 [dmcneil]
cygri seemdsto agree that since we are in last call now, that all changes should be linked to working group / last call comments (?)
17:34:43 [dmcneil]
ashok: how do we account for each line in the spec, that is what WG decision led to this text?
17:34:52 [dmcneil]
cygri: could dig up the CVS commits
17:34:59 [cygri]
ACTION: cygri to email the group regarding cvs history and diffs
17:35:00 [trackbot]
Created ACTION-178 - Email the group regarding cvs history and diffs [on Richard Cyganiak - due 2011-12-20].
17:35:09 [dmcneil]
ashok: the issue is most relevant for handling formal objections
17:36:20 [cygri]
souri, it should be: cvs diff -r 1.162 -r 1.165 Overview.html
17:37:15 [dmcneil]
david: how can i see a diff between last call and now
17:37:27 [dmcneil]
cygri: csv committers can use cvs diff
17:37:33 [dmcneil]
there is also a way to generate html diffs
17:37:40 [dmcneil]
not as useful after a large number of changes
17:37:59 [dmcneil]
will make a diff of the entire thing to see what it looks like, but probably not useful
17:38:35 [cygri]
17:38:40 [dmcneil]
he can also produce specific diffs that we think are interesting
17:39:28 [dmcneil]
david: are there more changes coming
17:39:46 [dmcneil]
cygri: that link to remaining issues... each is expected to produce another change to the doc
17:40:00 [dmcneil]
ashok: will there be one commit for each?
17:40:12 [dmcneil]
cygri: generally, yes, but not always
17:40:54 [dmcneil]
ashok: can take two versions and understand the changes in light of the working group changes
17:41:01 [dmcneil]
david are you good with that?
17:41:10 [dmcneil]
david: sounds like i will need to read two version side-by-side
17:41:14 [dmcneil]
topic: ISSUE-75
17:41:30 [Ashok]
17:41:51 [dmcneil]
ashok: this is about tableName syntactic sugar
17:41:53 [Souri]
Whenever editors commit, they can email a summary of the diffs produced by the "cvs diff " command for others to see.
17:42:10 [dmcneil]
david had a proposal on this
17:42:15 [Ashok]
[ PROPOSAL: Resolve ISSUE-75 by removing the tableName syntactic sugar and simplifying the R2RML schema documentation and property table to reflect this. ]
17:42:27 [dmcneil]
any discussion?
17:42:48 [juansequeda]
17:42:53 [dmcneil]
is this acceptable to the group? can we close ISSUE-75 with this proposal?
17:43:13 [ericP]
-> HTML diff of LC to editor's draft
17:43:15 [Souri]
+1 to removing this sugar
17:43:18 [dmcneil]
juan: is this something we expect to come back when users start using it?
17:43:22 [dmcneil]
ashok: who can tell?
17:43:47 [Ashok]
ack next
17:43:51 [dmcneil]
juan: well richard has experience with it, but i am fine with removing it
17:44:00 [Ashok]
ack next
17:44:34 [dmcneil]
cygri: ok with dropping it because it is a very minor issue, just one little thing for each triple map, not worth a big fight
17:45:03 [dmcneil]
ericP - yes!
17:45:06 [Souri]
17:45:12 [dmcneil]
ashok: any objections?
17:45:40 [dmcneil]
souri: so this means we will not have an rr:tableName hanging from triple maps directly, right?
17:46:15 [dmcneil]
ashok: no objections heard
17:46:29 [dmcneil]
RESOLUTION: Resolve ISSUE-75 by removing the tableName syntactic sugar and simplifying the R2RML schema documentation and property table to reflect this.
17:46:55 [dmcneil]
ashok: three others on the agenda, 72, 57, 56 and 13 minutes
17:47:12 [dmcneil]
not worth starting 72, because it will be long/difficult
17:47:21 [dmcneil]
others are 57 and 68
17:47:50 [Souri]
URL please
17:48:19 [Ashok]
Topic: ISSUE-68: Multiple PredicateMaps in a PredicateObjectMap
17:48:43 [Souri]
17:49:29 [cygri]
17:49:50 [dmcneil]
souri: if we do this special case, why not others, we don't need this
17:49:52 [Souri]
ack souri
17:50:13 [Ashok]
ack next
17:50:17 [Souri]
P{+}O, PO{+}, ...
17:50:23 [dmcneil]
cygri: with syntactic sugar, it is always a tradeoff and always subjective
17:50:34 [dmcneil]
but there will be some people who are quite happy to have it
17:50:52 [dmcneil]
there are many things that are effecticely sugar, e.g. templates, etc.
17:50:59 [dmcneil]
17:51:12 [dmcneil]
we could drop this wihtout expressivity, but it would make mapping harder
17:51:33 [dmcneil]
the question is: is the WG convinced that the sugar is not too confusing or complicated and provided enough value, always a judgement call
17:52:13 [dmcneil]
cygri: this feature is a poor man's RDF schema inferencing
17:52:21 [dmcneil]
e.g. employee class from db
17:52:28 [dmcneil]
employee is a sub-class of foaf:person
17:52:44 [dmcneil]
map that to rdf and do rdf schema inferencing to pick up foaf:agent
17:52:55 [dmcneil]
without rdf schema inference engine as part of r2rml implementation
17:53:03 [dmcneil]
users can just specify all the types in the mapping file
17:53:24 [dmcneil]
with class you can do this, because multiple classes are allowed per triplesmap
17:53:34 [dmcneil]
but the same thing holds for sub-properties
17:54:15 [Souri]
you can have a single object map URI, and then use multiple POmaps each referring to the same object map URI
17:54:23 [dmcneil]
it would be convenient to be able to list this like we can list multiple classes
17:54:43 [dmcneil]
ashok: what about souri's idea to also allow multiple objects?
17:54:50 [dmcneil]
cygri: that is not needed for rdfs inferencing
17:55:01 [Souri]
17:55:11 [dmcneil]
ashok: but as a question of symmetry?
17:55:23 [dmcneil]
cygri: symmetry not very important
17:55:43 [dmcneil]
souri: it is not as hard as you think to do this without the sugar
17:56:00 [dmcneil]
see souri's comment above
17:56:33 [dmcneil]
the main pattern of s, p, o... if we allow s, p+, o... why not s,p,o+
17:56:41 [dmcneil]
and once we add a shortcut, we can never take it away
17:56:59 [dmcneil]
this is version 1.0, we are not losing any expressivity, don't see the need for a shortcut at this point, in 1.0
17:57:24 [dmcneil]
cygri: turtle is a representation format, not a mapping language so the analogy does not apply
17:57:33 [dmcneil]
re: how complicated it is without sugar:
17:57:41 [Souri]
17:57:50 [dmcneil]
in D2RQ people use a mapping generator that produces a skeleton that is customized
17:58:05 [dmcneil]
really nice to go in there and just change the autogenerated property name
17:58:11 [dmcneil]
and just add another property name
17:58:36 [dmcneil]
many users don't understand D2RQ mapping language, but they do know how to change properties in a generated mapping
17:58:53 [dmcneil]
so it is quite easy to replace one name with a few names
17:59:08 [dmcneil]
but creating new resources and wiring them up is much harder and requires an understanding of the language
17:59:11 [dmcneil]
and of turtle
17:59:17 [Souri]
17:59:25 [dmcneil]
which is a much higher barrier to creating mapping
17:59:32 [dmcneil]
graphical editors will not exist overnight
18:00:03 [dmcneil]
also, implementing this feature is not hard, can just explode it out in the graph, it is not a big deal
18:00:09 [dmcneil]
we did this in D2RQ
18:00:41 [dmcneil]
souri: regarding the analogy to turtle
18:01:44 [dmcneil]
there are other uses and other perspectives
18:02:17 [dmcneil]
users spend much more time debugging there code, not the mapping
18:02:29 [dmcneil]
18:02:30 [MacTed]
different kinds of "users"
18:02:50 [juansequeda]
Let's leave any type of syntactic sugar and short cuts for R2RML 1.1
18:02:51 [MacTed]
exactly -- implementors vs users of implementations
18:03:06 [dmcneil]
cygri: not worried about spec author's time, not worried about implementor's time so much, most worried about users time
18:03:25 [dmcneil]
if implementor can do some extra work to save a lot of complexity for users, then that is a good thing
18:03:33 [Souri]
why not SPO{+} then? I do not find this "that" beneficial!
18:03:42 [dmcneil]
regarding predicates vs objects, the symmetry is not important
18:03:46 [Souri]
I am not arguing for symmetry
18:04:04 [Souri]
SPO{+} is important and pretty common
18:04:12 [MacTed]
not just saving time -- also removing potentially large barrier to entry/usage.
18:04:12 [MacTed]
I think the SPO{+} is also valuable, but not because it's symmetric
18:04:33 [dmcneil]
ashok: we are out of time
18:04:47 [dmcneil]
we can't resolve this today
18:05:05 [dmcneil]
juan suggested holding off on sugar until 1.1
18:05:20 [dmcneil]
we have this issue plus ISSUE-72 and ISSUE-57
18:05:40 [dmcneil]
we have to resolve these... please think about what you can do and what compromises can be made
18:05:45 [Souri]
for ISSUE-72 please see URL:
18:06:05 [Zakim]
18:06:06 [Zakim]
18:06:07 [Zakim]
18:06:07 [Zakim]
18:06:09 [Zakim]
18:06:12 [Zakim]
18:06:23 [Ashok]
Sorry, I introduced the word "symmetry" --- perhaps that was inappropriate
18:06:39 [Ashok]
rrsagent, make logs public
18:06:55 [Ashok]
rrsagent, draft minutes
18:06:55 [RRSAgent]
I have made the request to generate Ashok
18:07:07 [Zakim]
18:40:37 [cygri]
ACTION: boris to review test cases for any that use rr:tableName, rr:sqlQuery or rr:sqlVersion directly on a triples maps; this syntactic sugar is removed by the ISSUE-75 resolution
18:40:38 [trackbot]
Created ACTION-179 - Review test cases for any that use rr:tableName, rr:sqlQuery or rr:sqlVersion directly on a triples maps; this syntactic sugar is removed by the ISSUE-75 resolution [on Boris Villazón-Terrazas - due 2011-12-20].
18:40:44 [cygri]
18:40:44 [trackbot]
ACTION-179 -- Boris Villazón-Terrazas to review test cases for any that use rr:tableName, rr:sqlQuery or rr:sqlVersion directly on a triples maps; this syntactic sugar is removed by the ISSUE-75 resolution -- due 2011-12-20 -- OPEN
18:40:44 [trackbot]
19:05:00 [Zakim]
disconnecting the lone participant, EricP, in SW_RDB2RDF()12:00PM
19:05:01 [Zakim]
SW_RDB2RDF()12:00PM has ended
19:05:05 [Zakim]
Attendees were Ashok_Malhotra, dmcneil, juansequeda, cygri, nunolopes, Souri, MacTed, Seema, EricP
19:31:02 [nunolopes]
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