15:54:07 <RRSAgent> RRSAgent has joined #rdb2rdf
15:54:08 <RRSAgent> logging to http://www.w3.org/2010/09/21-rdb2rdf-irc
15:54:09 <trackbot> RRSAgent, make logs world
15:54:10 <Zakim> Zakim has joined #rdb2rdf
15:54:11 <trackbot> Zakim, this will be 7322733
15:54:11 <Zakim> ok, trackbot; I see SW_RDB2RDF()12:00PM scheduled to start in 6 minutes
15:54:12 <trackbot> Meeting: RDB2RDF Working Group Teleconference
15:54:13 <trackbot> Date: 21 September 2010
15:54:31 <mhausenblas> Agenda: http://lists.w3.org/Archives/Public/public-rdb2rdf-wg/2010Sep/0048.html
15:58:01 <mhausenblas> Chair: Ashok
15:58:07 <mhausenblas> RRSAgent, draft minutes
15:58:07 <RRSAgent> I have made the request to generate http://www.w3.org/2010/09/21-rdb2rdf-minutes.html mhausenblas
15:58:14 <mhausenblas> RRSAgent, make logs public
15:58:29 <Ashok> Ashok has joined #rdb2rdf
15:59:04 <juansequeda> juansequeda has joined #rdb2rdf
15:59:38 <Zakim> SW_RDB2RDF()12:00PM has now started
15:59:44 <Zakim> + +1.512.232.aaaa
15:59:45 <Ashok> meeting:  RDB2RDF
15:59:47 <Zakim> - +1.512.232.aaaa
15:59:48 <Zakim> SW_RDB2RDF()12:00PM has ended
15:59:48 <Zakim> Attendees were +1.512.232.aaaa
15:59:56 <Zakim> SW_RDB2RDF()12:00PM has now started
16:00:03 <Zakim> +mhausenblas
16:00:06 <Souri> Souri has joined #rdb2rdf
16:00:25 <nunolopes> nunolopes has joined #RDB2RDF
16:00:27 <Zakim> + +49.133.6.aaaa
16:00:27 <Zakim> + +1.512.232.aabb
16:00:31 <Zakim> +OpenLink_Software
16:00:47 <soeren> soeren has joined #RDB2RDF
16:00:48 <MacTed> Zakim, OpenLink_Software is temporarily me
16:00:52 <MacTed> Zakim, mute me
16:00:53 <Zakim> +Ashok_Malhotra
16:00:53 <ericP> Zakim, please dial ericP-office
16:00:54 <juansequeda> Zakim, aaaa is me
16:00:59 <Zakim> +MacTed; got it
16:01:03 <Zakim> MacTed should now be muted
16:01:06 <Zakim> ok, ericP; the call is being made
16:01:09 <Zakim> +juansequeda; got it
16:01:09 <mhausenblas> Zakim, who's here?
16:01:11 <Zakim> +EricP
16:01:14 <Zakim> On the phone I see mhausenblas, juansequeda, +1.512.232.aabb, MacTed (muted), Ashok_Malhotra, EricP
16:01:19 <Zakim> On IRC I see soeren, Souri, juansequeda, Ashok, Zakim, RRSAgent, boris, hhalpin, mhausenblas, MacTed, iv_an_ru, ericP, trackbot
16:01:28 <Ashok> regrets:  Li_Ma, Wolfgang_Halb
16:01:36 <mhausenblas> RRSAgent, draft minutes
16:01:36 <RRSAgent> I have made the request to generate http://www.w3.org/2010/09/21-rdb2rdf-minutes.html mhausenblas
16:01:40 <Zakim> +Souri_Das
16:01:45 <nunolopes> nunolopes has joined #RDB2RDF
16:01:48 <Zakim> +??P46
16:01:56 <mhausenblas> scribenick: mhausenblas 
16:02:02 <mhausenblas> Zakim, nunolopes is with mhausenblas 
16:02:02 <Zakim> +nunolopes; got it
16:02:13 <boris> Zakim, aabb is me
16:02:14 <Zakim> +boris; got it
16:02:20 <hhalpin> Zakim, ??P45 is hhalpin
16:02:20 <Zakim> I already had ??P45 as +1.209.474.aabb, hhalpin
16:02:26 <hhalpin> Zakim, ??P46 is hhalpin
16:02:26 <Zakim> +hhalpin; got it
16:02:41 <hhalpin> Zakim, who is making noise?
16:02:44 <Souri> zakim, souri_das is me
16:02:50 <Zakim> +Souri; got it
16:02:53 <mhausenblas> RRSAgent, draft minutes
16:02:53 <RRSAgent> I have made the request to generate http://www.w3.org/2010/09/21-rdb2rdf-minutes.html mhausenblas
16:02:58 <Zakim> hhalpin, listening for 10 seconds I heard sound from the following: juansequeda (15%)
16:03:28 <Zakim> + +49.341.973.aacc
16:03:44 <soeren> zakim, aacc is soeren
16:03:46 <Zakim> +soeren; got it
16:03:56 <juansequeda> zakim, mute me
16:03:57 <Zakim> juansequeda should now be muted
16:04:14 <Souri> zakim, mute me
16:04:14 <Zakim> Souri should now be muted
16:04:14 <mhausenblas> Agenda is at http://lists.w3.org/Archives/Public/public-rdb2rdf-wg/2010Sep/0048.html
16:04:25 <mhausenblas> Topic: Admin
16:04:43 <ericP> ericP has changed the topic to: RDB2RDF telecon -- agenda: http://lists.w3.org/Archives/Public/public-rdb2rdf-wg/2010Sep/0048
16:04:55 <mhausenblas> PROPOSAL: Accept the minutes of last meeting, see http://www.w3.org/2010/09/14-rdb2rdf-minutes.html
16:05:12 <hhalpin> +1
16:05:19 <cygri> cygri has joined #rdb2rdf
16:05:21 <boris> zakim, mute me
16:05:21 <Zakim> boris should now be muted
16:05:27 <mhausenblas> RESOLUTION: WG has accepted the minutes from last time
16:05:40 <mhausenblas> Topic: Change name of language to SQRL?
16:05:47 <mhausenblas> Zakim, cygri is with mhausenblas 
16:05:47 <Zakim> +cygri; got it
16:06:02 <mhausenblas> Michael: let's focus on FPWD for now
16:06:31 <hhalpin> my main comment is to leave that to the editors
16:06:57 <mhausenblas> Ashok: second that
16:07:08 <mhausenblas> Topic: Any comments on FPWD
16:07:42 <Souri> I have not had much time to work on it due to OOW
16:07:44 <mhausenblas> Ashok: Souri, Seema and Richard are working on it  - any comments?
16:08:02 <mhausenblas> ericP: still some issues re CVS, we're working on it
16:08:16 <mhausenblas> hhalpin: do all editor have CVS working?
16:08:28 <Souri> zakim, unmute me
16:08:28 <Zakim> Souri should no longer be muted
16:08:39 <mhausenblas> cygri: I believe it should be working now, yes -  sent credentials to ericP 
16:08:55 <mhausenblas> Michael: I can assist, yes
16:09:22 <mhausenblas> hhalpin: Souri and Seema?
16:09:24 <ericP> cygri, all three of you will get email when the sysfolks have dealt with the request
16:10:13 <hhalpin> straight XHTML
16:10:28 <mhausenblas> cygri: editors will sort out, yes
16:10:52 <mhausenblas> Souri: got hhalpin mail but not yet tested it
16:11:09 <hhalpin> next week is fine for me.
16:11:33 <Souri> zakim, mute me
16:11:33 <Zakim> Souri should now be muted
16:11:36 <mhausenblas> Ashok: so question is - are we on track for a FPWD by end of month?
16:11:53 <mhausenblas> cygri: how much content would you expect?
16:12:19 <Souri> zakim, unmute me
16:12:19 <Zakim> Souri should no longer be muted
16:12:21 <mhausenblas> Ashok: a skeleton would be sufficient
16:12:34 <ericP> it's a balance between getting early feedback and taking advantage of an opportunity to make a splash
16:12:44 <mhausenblas> cygri: will have this and a lot of details not yet nailed down I 
16:13:10 <mhausenblas> Ashok: completely fine if FPWD has questions/comments in there
16:13:38 <mhausenblas> hhalpin: would be good to have a something out there by end of week (heart beat requirement)
16:13:44 <mhausenblas> RRSAgent, draft minutes
16:13:44 <RRSAgent> I have made the request to generate http://www.w3.org/2010/09/21-rdb2rdf-minutes.html mhausenblas
16:14:17 <mhausenblas> hhalpin: gather early feedback
16:14:21 <hhalpin> heartbeat check/schedule by Sept 30th.
16:14:26 <mhausenblas> Topic: R2RML Semantics and direct mapping
16:14:51 <Souri> zakim, mute me
16:14:51 <Zakim> Souri should now be muted
16:15:01 <mhausenblas> Ashok: I'd prefer to have the semantics right after FPWD
16:15:13 <mhausenblas> Ashok: so this week we have ericP on the call
16:15:25 <juansequeda> Eric has been talking with Marcelo (... right?)
16:15:27 <mhausenblas> ... did you and juansequeda agree on semantics, yet?
16:16:03 <mhausenblas> ericP: trying to balance against the Datalog one
16:16:22 <mhausenblas> ... couple of issues (PK, FK to tuple, etc.)
16:16:33 <juansequeda> zakim, unmute me
16:16:33 <Zakim> juansequeda should no longer be muted
16:16:58 <mhausenblas> Ashok: what doc are you referring to?
16:18:10 <mhausenblas> ericP: the maths for creating URI is plain English (?)
16:18:17 <hhalpin> I would like to see EricP list out these issues in IRC.
16:18:36 <mhausenblas> ... still believe the set notation would be more sound
16:18:41 <mhausenblas> q?
16:18:44 <juansequeda> q+
16:18:58 <mhausenblas> ack juansequeda 
16:19:04 <Ashok> present:  Souri, Richard, Juan, EricP, Michael. Ashok, Harry, Boris, Ivan, Ted, Nuno
16:19:08 <juansequeda> yes
16:19:18 <juansequeda> having problems with my phoen
16:19:19 <hhalpin> q+
16:19:19 <MacTed> Zakim, unmute juansequeda
16:19:20 <Zakim> juansequeda was not muted, MacTed
16:19:21 <juansequeda> can you here me?
16:19:30 <juansequeda> im going to redail
16:19:33 <Zakim> -boris
16:19:39 <mhausenblas> q?
16:19:40 <hhalpin> ack hhalpin
16:19:58 <Zakim> +boris
16:20:24 <mhausenblas> hhalpin: would be good if we go with the approach the majority of the WG prefers
16:20:32 <MacTed> q+
16:20:36 <mhausenblas> ... can ericP list the issues?
16:20:40 <mhausenblas> q?
16:20:43 <juansequeda> I talked to several people at Microsoft
16:20:54 <juansequeda> they said either Datalog or even relational algebra
16:21:15 <mhausenblas> q?
16:21:16 <MacTed> q+ to suggest that Eric's metric of usability may be overambitious
16:21:23 <mhausenblas> q?
16:21:38 <mhausenblas> juansequeda: ericP was working with Marcello 
16:21:48 <mhausenblas> ericP: we exchanged a bunch of documents, yes
16:22:36 <mhausenblas> juansequeda: talked to MS people, for them Datalog is fine or relational algebra
16:22:49 <mhausenblas> ... want to approach IBM people
16:23:08 <mhausenblas> soeren: think relational algebra would be easier to understand
16:23:19 <Ashok> present+: Soeren
16:23:28 <mhausenblas> ... I already sent a draft 
16:23:54 <mhausenblas> juansequeda: response I got was half half (between datalog and relational algebra)
16:24:00 <mhausenblas> q?
16:24:47 <mhausenblas> hhalpin: more or less same in the DB group in Edinburgh 
16:25:03 <hhalpin> the point is they can generally be made equivalent
16:25:04 <mhausenblas> juansequeda: seems to be two camps
16:25:14 <mhausenblas> ... we can put them side by side
16:25:33 <mhausenblas> soeren: I like both but relational algebra would be easier to read
16:25:48 <mhausenblas> RRSAgent, draft minutes
16:25:48 <RRSAgent> I have made the request to generate http://www.w3.org/2010/09/21-rdb2rdf-minutes.html mhausenblas
16:26:10 <hhalpin> These are the issues that need to be iterated.
16:26:34 <mhausenblas> ericP: I see quite some issues that might require a lot of hand waving (re bNodes, etc.)
16:26:43 <MacTed> q-
16:26:49 <Souri> +1 to having both and then comparing side by side (taking into account EricP's comment about no-primary-key case handling)
16:27:09 <mhausenblas> juansequeda: need to think about the limitations mentioned by ericP 
16:27:19 <mhausenblas> ... would be good if ericP sends out a list
16:27:29 <mhausenblas> ... of cases where he sees issues
16:27:32 <mhausenblas> q?
16:28:00 <MacTed> Zakim, unmute me
16:28:00 <Zakim> MacTed should no longer be muted
16:28:39 <MacTed> Zakim, mute me
16:28:39 <Zakim> MacTed should now be muted
16:28:47 <mhausenblas> MacTed: not sure if it is worth it determining if it is readable
16:29:06 <ericP> no pk: http://www.w3.org/2001/sw/rdb2rdf/directGraph/#no-pk
16:29:22 <mhausenblas> ACTION: Eric to list issues re Datalog approach re PK, FK, etc
16:29:22 <trackbot> Created ACTION-72 - List issues re Datalog approach re PK, FK, etc [on Eric Prud'hommeaux - due 2010-09-28].
16:30:08 <hhalpin> What would be the identifier then?
16:30:14 <mhausenblas> juansequeda: talked with Marcello; he was against using a bNode for this (see also RDF next steps workshop)
16:30:28 <MacTed> default primary key = ROWID, which is RDB implementation dependent
16:30:46 <MacTed> when there's no such, concatenation of all fields is sometimes (often) used as a fallback
16:30:49 <mhausenblas> ericP: I can give you examples where this is needed
16:30:55 <hhalpin> good point MacTed
16:31:00 <MacTed> if there's no unique on that concat, then problems arise ... but there are problems already
16:32:06 <Souri> we would need to generate unique bNode label for each row (uniqueness is limited to the desitination graph)
16:32:17 <mhausenblas> ericP: just to give a scope on the problem - assume the RDB as dataware house,  in this multi set case you run into issues
16:32:42 <mhausenblas> Ashok: re MacTed's comment
16:32:54 <Souri> zakim, unmute me
16:32:54 <Zakim> Souri should no longer be muted
16:33:00 <MacTed> "implementation dependent"  :-)
16:33:05 <Souri> q+
16:33:10 <mhausenblas> Ashok: ROWID can change, hence not possible
16:33:13 <mhausenblas> q?
16:33:32 <mhausenblas> ack Souri  
16:34:01 <mhausenblas> Souri: basic problem is that we don't have PK we need to identify each row
16:34:12 <mhausenblas> ... can be limited to destination graph
16:34:33 <mhausenblas> Souri: just thinking aloud now - if we say the ROWID is the bNode ID
16:34:46 <mhausenblas> ... so could might have moved
16:35:27 <mhausenblas> ... seems like it would work out for SPARQL query
16:35:37 <mhausenblas> ... but not totally sure
16:35:59 <ericP> q+ to suggest how a blank node is interpreted in SQL
16:36:09 <mhausenblas> juansequeda: if there is no PK, how do I get all the data?
16:36:22 <mhausenblas> Souri: can't get it from the RDB
16:36:32 <mhausenblas> q?
16:36:51 <mhausenblas> Souri: the bNode could cluster all the relevant data
16:37:00 <mhausenblas> ... in subject position
16:37:28 <hhalpin> q+
16:37:33 <mhausenblas> ack ericP 
16:37:33 <Zakim> ericP, you wanted to suggest how a blank node is interpreted in SQL
16:38:04 <mhausenblas> ericP: in SQL-land I can't identify a non-PK row
16:38:20 <mhausenblas> ... same in RDF-land
16:39:01 <mhausenblas> ... but in SPARQL/SQL update I can do it
16:39:05 <mhausenblas> q?
16:39:30 <mhausenblas> juansequeda: a bNode identifies something, but in SQL we don't have the same
16:39:43 <mhausenblas> Souri: I disagree; the raw boundary is there
16:39:51 <mhausenblas> s/raw/row
16:40:32 <mhausenblas> Souri: but we need a unique subject
16:40:56 <mhausenblas> juansequeda: I agree, yes - will check back with Marcello, as he has some reservation re this
16:40:56 <hhalpin> http://www.w3.org/2009/12/rdf-ws/papers/ws23
16:41:00 <Souri> q+
16:41:04 <mhausenblas> q?
16:41:07 <mhausenblas> ack hhalpin 
16:41:48 <mhausenblas> hhalpin: the semantics are a bit different though (PatH vs. Marcello)
16:41:59 <mhausenblas> q?
16:42:20 <mhausenblas> s/PatH vs. Marcello/PatH agrees with Marcello re this
16:42:49 <Zakim> -soeren
16:42:57 <mhausenblas> hhalpin: so, whatever is the simplest solution is fine with me (sort of ignoring the original semantics)
16:43:02 <Souri> From practitioners point of view, the main difference between bNode and URI is one has a local (graph) scope and the other has global scope
16:43:11 <Souri> q-
16:43:15 <mhausenblas> ericP: so, hhalpin, which semantics are we talking about, then?
16:44:02 <mhausenblas> hhalpin: we should use it in a practical way
16:44:19 <ericP> Debtors:
16:44:19 <ericP> Bob Smith  $30
16:44:19 <ericP> Bob Smith  $30
16:44:19 <ericP> Debtors: { [ :fn "Bob" ; :ln "Smith" ; :amnt ] [ :fn "Bob" ; :ln "Smith" ; :amnt ] }
16:44:21 <mhausenblas> juansequeda: agree. need to identify and discuss issues
16:44:22 <ericP> SELECT SUM(amnt) FROM Debtors WHERE fn = "Bob" AND ln = "Smith"
16:44:24 <ericP> SELECT (SUM(amnt) AS ?a) { [ :fn "Bob" ; :ln "Smith"] }
16:44:56 <hhalpin> i.e. the existential variable interpretation is a bit silly, but the blank nodes are generally used for "grouping" data that doesn't otherwise have an identifier.
16:44:57 <mhausenblas> ericP: on a per-use cases basis decide on issues/coverage
16:45:05 <Souri> if we generate bNode, we need to ensure the uniqueness is maintained within each destination graph, if we use URIs uniqueness has to be global
16:45:17 <mhausenblas> RRSAgent, draft minutes
16:45:17 <RRSAgent> I have made the request to generate http://www.w3.org/2010/09/21-rdb2rdf-minutes.html mhausenblas
16:45:43 <hhalpin> that's a good point Souri - i.e. why we need to consider the blank node semantically as basically a unique identifier...
16:45:52 <Souri> zakim, mute me
16:45:52 <Zakim> Souri should now be muted
16:46:28 <hhalpin> however, again, that bring's up the issue with MacTed's concat common practice
16:46:31 <Souri> zakim, unmute me
16:46:31 <Zakim> Souri should no longer be muted
16:46:33 <Souri> q+
16:46:39 <mhausenblas> ack Souri 
16:47:31 <mhausenblas> Souri: from practitioners POV, URI is a bit more complex -  all we need to ensure the 'label' we produce is unique in the destination graph 
16:47:33 <mhausenblas> q?
16:48:39 <mhausenblas> (scribe missed the details of Souri's explanation)
16:49:27 <mhausenblas> ericP: I guess the most complex scenario is with FK
16:49:29 <hhalpin> q+
16:49:49 <mhausenblas> ericP: FK have to reference candidate key
16:50:02 <mhausenblas> ... could be a bNode
16:51:23 <mhausenblas> ericP: so unclear how to deal with the materialisation 
16:51:35 <mhausenblas> Souri: tough case indeed, need to think more about it
16:51:57 <mhausenblas> ericP: it's doable, just an extra step
16:52:39 <mhausenblas> Souri: I was thinking of having a joint condition -  if there is no corresponding on the PK, then don't know how to generate it
16:52:41 <mhausenblas> q?
16:52:59 <mhausenblas> juansequeda: need to distinguish default mapping and customisation
16:53:21 <mhausenblas> ericP: right, and we might write some UC out of the default mapping
16:53:51 <hhalpin> ack hhalpin
16:53:54 <mhausenblas> Souri: we need to explicitly say what we can handle (the editors)
16:53:57 <mhausenblas> q?
16:54:17 <mhausenblas> hhalpin: edge cases need to be addressed (test cases)
16:54:57 <mhausenblas> ... need to highlight these cases (not only formally)
16:55:15 <mhausenblas> ... agree with MacTed's point there
16:55:33 <mhausenblas> juansequeda: agree as well
16:55:39 <mhausenblas> q?
16:55:42 <Souri> I agree to Harry about the edge cases
16:55:45 <mhausenblas> RRSAgent, draft minutes
16:55:45 <RRSAgent> I have made the request to generate http://www.w3.org/2010/09/21-rdb2rdf-minutes.html mhausenblas
16:55:47 <hhalpin> not hide edge-cases in formal semantics
16:56:02 <hhalpin> even if they are there, but we need to warn implenters about them
16:56:05 <mhausenblas> Souri: need to be explicit about the edge cases, yes
16:56:38 <ericP> q+
16:56:57 <mhausenblas> ack ericP
16:57:25 <mhausenblas> ericP: the scenario I just gave above is actually a combination of two more basic ones
16:57:31 <ericP> http://www.w3.org/2001/sw/rdb2rdf/directGraph/#no-pk
16:57:50 <Souri> q+
16:58:42 <mhausenblas> ack Souri 
16:59:01 <mhausenblas> juansequeda: will send out paper about this and sync with ericP 
16:59:43 <mhausenblas> (Souri explains another joint-condition example)
16:59:50 <ericP> "The columns in the referencing table must be the primary key or other candidate key in the referenced table." — http://en.wikipedia.org/wiki/Foreign_key
17:00:02 <ericP> ('cause I can't paste from Date)
17:01:54 <mhausenblas> Ashok: ok, thanks for all the input - we have our action items, will not be here next week
17:02:00 <mhausenblas> Michael: I'm around
17:02:03 <Zakim> -EricP
17:02:04 <Zakim> -Souri
17:02:05 <mhausenblas> [adjourned]
17:02:06 <Zakim> -MacTed
17:02:06 <Zakim> -Ashok_Malhotra
17:02:07 <Zakim> -boris
17:02:09 <Zakim> -mhausenblas
17:02:16 <mhausenblas> trackbot, end telecon
17:02:16 <trackbot> Zakim, list attendees
17:02:16 <Zakim> As of this point the attendees have been mhausenblas, +49.133.6.aaaa, +1.512.232.aabb, Ashok_Malhotra, MacTed, juansequeda, EricP, nunolopes, boris, hhalpin, Souri,
17:02:17 <trackbot> RRSAgent, please draft minutes
17:02:17 <RRSAgent> I have made the request to generate http://www.w3.org/2010/09/21-rdb2rdf-minutes.html trackbot
17:02:18 <trackbot> RRSAgent, bye
17:02:18 <RRSAgent> I see 1 open action item saved in http://www.w3.org/2010/09/21-rdb2rdf-actions.rdf :
17:02:18 <RRSAgent> ACTION: Eric to list issues re Datalog approach re PK, FK, etc [1]
17:02:18 <RRSAgent>   recorded in http://www.w3.org/2010/09/21-rdb2rdf-irc#T16-29-22
17:02:19 <Zakim> ... +49.341.973.aacc, soeren, cygri
17:02:19 <Zakim> -juansequeda
17:02:20 <Zakim> -hhalpin
17:02:20 <Zakim> SW_RDB2RDF()12:00PM has ended
17:02:21 <Zakim> Attendees were mhausenblas, +49.133.6.aaaa, +1.512.232.aabb, Ashok_Malhotra, MacTed, juansequeda, EricP, nunolopes, boris, hhalpin, Souri, +49.341.973.aacc, soeren, cygri