16:37:21 RRSAgent has joined #rdb2rdf 16:37:21 logging to http://www.w3.org/2011/02/01-rdb2rdf-irc 16:37:23 RRSAgent, make logs world 16:37:23 Zakim has joined #rdb2rdf 16:37:25 Zakim, this will be 7322733 16:37:25 ok, trackbot; I see SW_RDB2RDF()12:00PM scheduled to start in 23 minutes 16:37:26 Meeting: RDB2RDF Working Group Teleconference 16:37:26 Date: 01 February 2011 16:37:34 Agenda: http://lists.w3.org/Archives/Public/public-rdb2rdf-wg/2011Jan/0080.html 16:37:39 Chair: Michael 16:59:23 Ashok has joined #rdb2rdf 17:00:25 boris has joined #rdb2rdf 17:00:26 juansequeda has joined #rdb2rdf 17:00:54 Zakim, code? 17:00:54 the conference code is 7322733 (tel:+1.617.761.6200 tel:+33.4.26.46.79.03 tel:+44.203.318.0479), mhausenblas 17:01:01 Souri has joined #rdb2rdf 17:01:31 SW_RDB2RDF()12:00PM has now started 17:01:38 +boris 17:01:39 +juansequeda 17:01:52 +mhausenblas 17:02:00 + +1.636.544.aaaa 17:02:02 +Ashok_Malhotra 17:02:04 who is here 17:02:08 soeren has joined #RDB2RDF 17:02:14 zakim, who is here 17:02:15 boris, you need to end that query with '?' 17:02:17 +souri 17:02:28 zakim, who is here? 17:02:28 On the phone I see boris, juansequeda, mhausenblas, +1.636.544.aaaa, Ashok_Malhotra, souri 17:02:31 On IRC I see soeren, Souri, juansequeda, boris, Ashok, Zakim, RRSAgent, cygri, mhausenblas, ivan, MacTed, LeeF, betehess, iv_an_ru, trackbot, ericP 17:02:33 + +1.284.612.aabb 17:02:43 Seema has joined #rdb2rdf 17:03:03 +Alexandre 17:03:16 Zakim, who's here? 17:03:16 On the phone I see boris, juansequeda, mhausenblas, +1.636.544.aaaa, Ashok_Malhotra, souri, +1.284.612.aabb, Alexandre 17:03:18 On IRC I see Seema, soeren, Souri, juansequeda, boris, Ashok, Zakim, RRSAgent, cygri, mhausenblas, ivan, MacTed, LeeF, betehess, iv_an_ru, trackbot, ericP 17:03:20 + +1.603.891.aacc 17:03:44 Zakim, aacc is Seema 17:03:44 +Seema; got it 17:03:46 dmcneil has joined #RDB2RDF 17:04:08 Zakim, please dial ericP-office 17:04:08 ok, ericP; the call is being made 17:04:10 +EricP 17:04:26 Zakim, aaaa is dmcneil 17:04:26 +dmcneil; got it 17:04:41 Zakim, aabb is soeren 17:04:41 +soeren; got it 17:04:55 Zakim, pick a victim 17:04:55 Not knowing who is chairing or who scribed recently, I propose boris 17:05:11 so 17:05:36 scribenick: cygri 17:05:41 -soeren 17:05:45 http://lists.w3.org/Archives/Public/public-rdb2rdf-wg/2011Jan/0080.html 17:05:57 Topic: 1. Admin 17:06:04 PROPOSAL: Accept the minutes of last meeting, see 17:06:04 http://www.w3.org/2011/01/25-rdb2rdf-minutes.html 17:06:16 + +886201aadd 17:06:26 Zakim, aadd is soeren 17:06:26 +soeren; got it 17:06:32 zakim, dial ivan-voip 17:06:32 ok, ivan; the call is being made 17:06:34 +Ivan 17:06:49 +1 17:06:49 I+1 17:06:50 +1 17:06:50 +1 17:06:52 RESOLUTION: Accept the minutes of last meeting, see http://www.w3.org/2011/01/25-rdb2rdf-minutes.html 17:07:02 Topic: 2. Direct Mapping status 17:07:15 regrets+ Marcelo 17:07:22 ACTION-85? 17:07:23 ACTION-85 -- Ted Thibodeau to review Direct Mapping ED -- due 2011-02-01 -- OPEN 17:07:23 http://www.w3.org/2001/sw/rdb2rdf/track/actions/85 17:07:28 regrets+ Percy 17:07:55 Zakim, who's here? 17:07:55 On the phone I see boris, juansequeda, mhausenblas, dmcneil, Ashok_Malhotra, souri, Alexandre, Seema, EricP, soeren, Ivan 17:07:57 On IRC I see dmcneil, Seema, soeren, Souri, juansequeda, boris, Ashok, Zakim, RRSAgent, cygri, mhausenblas, ivan, MacTed, LeeF, betehess, iv_an_ru, trackbot, ericP 17:08:02 MacTed? 17:08:24 drop ACTION-85 17:08:30 close ACTION-85 17:08:30 ACTION-85 Review Direct Mapping ED closed 17:08:34 http://www.w3.org/2001/sw/rdb2rdf/directMapping/ 17:09:05 http://www.w3.org/2001/sw/rdb2rdf/track/issues/raised 17:09:33 mhausenblas: let's go through raised issues for the direct mapping 17:09:49 ... for each issue, let's get them from "raised" to "open", "postponed", "closed" etc 17:09:52 http://www.w3.org/2001/sw/rdb2rdf/track/issues/9 17:09:57 ISSUE-9? 17:09:58 ISSUE-9 -- Generate Blank Nodes for duplicate tuples -- raised 17:09:58 http://www.w3.org/2001/sw/rdb2rdf/track/issues/9 17:10:46 juansequeda: Marcelo and I currently use a predicate that states the cardinality 17:11:03 ... in section 4.1, 4.2 17:11:05 q+ 17:11:11 ... we ask people to review this 17:11:14 ack betehess 17:11:49 betehess: let's be careful not to call this solved, it interacts with other issues i have in the queue 17:11:58 Michael: looks like we should change the issue 9 from raised to open 17:13:43 betehess: i don't understand how to play with the datalog rules in order to execute them 17:14:06 mhausenblas: let's not do very generic issues 17:14:50 uri? 17:14:55 http://www.w3.org/2001/sw/rdb2rdf/directMapping/ 17:14:56 juansequeda: we added examples for 4.1 and 4.2 17:15:16 ... that should help clarify. if there are still problems with this, please raise 17:15:32 ericP: test cases please 17:15:32 Michael: I encourage everyone to raise issues no matter if there exists something on not, as long as it is concrete enough, please go ahead 17:15:42 nunolopes has joined #RDB2RDF 17:15:51 betehess: i don't recognize RDB or RDF in the rules 17:16:00 Zakim, nunolopes is with mhausenblas 17:16:00 +nunolopes; got it 17:16:08 q+ 17:16:10 juansequeda: RDB model is just some predicates 17:16:43 betehess: i don't think it's well-defined. two solutions in the document that work with sort of different data models 17:16:55 ... rdb model is more than just predicates 17:17:11 ... in datalog you need to state facts. i don't see this in the current version 17:17:16 ... it's not exactly datalog 17:17:35 ... don't see how to go from rdb to rdf using this 17:17:58 ack ivan 17:17:59 q? 17:18:27 ivan: the document says that we present rules in datalog *syntax*, so it may not use the formal mathematical model 17:18:42 ... it's just a set of rules. that's fine 17:19:05 ... we should show that both formalism lead to same triples from same db 17:19:13 +1 to a lot of testcases 17:19:22 ... how to do that? a boatload of testcases 17:20:06 mhausenblas: yes we need test cases to proceed. how to get them? 17:20:13 q? 17:20:19 ivan: we started with specific issues. put them in the issue list. 17:20:53 ... juan, are there ways for getting those rules rolling in a specific system? the other formalism has an implementation 17:21:03 http://www.w3.org/2001/sw/rdb2rdf/wiki/All_Cases_for_Default_Mapping 17:21:06 ... if we had a processor, we could run them side by side 17:21:27 mhausenblas: could this writeup be used as input for test cases? http://www.w3.org/2001/sw/rdb2rdf/wiki/All_Cases_for_Default_Mapping 17:21:37 q+ 17:21:43 juansequeda: just a list of cases that had to be managed 17:22:30 ... rules don't need to be implemented. it's an if-then case 17:22:41 ivan: we have to prove they do the same thing. how else would we do that? 17:23:04 ack boris 17:23:06 q+ 17:23:19 juansequeda: this just specifies some cases. if this, then that. doesn't have to be implemented using a rules engine. we don't expect people to do that 17:23:30 q? 17:23:48 boris: we started with very simple test cases, want to get on to more complex ones 17:23:59 mhausenblas: probably we want to prioritize direct mapping test cases 17:24:00 TaskAssignments 17:24:00 7 "pencil survey" "accounting" "Cambridge" 17:24:00 NULL "pencil survey" "accounting" "Cambridge" 17:24:01 ack Souri 17:24:28 Souri: as a practitioner, my experience is that blank nodes cause lots of problems 17:24:36 ... let's minimize generation of blank nodes 17:24:52 +1 17:25:11 ... we need to generate a unique label anyways. then we could just make a URI from it. makes life easier for implementers 17:25:17 note that the above table preserves UNIQUE(worker, project), but not PRIMARY KEY(worker, project) 17:25:57 q+ to say that unresolvable identifiers create issues 17:26:20 ... bnodes are local symbols in a graph, so if you make two triples in different graphs from same row, they don't merge 17:26:27 ack ericP 17:26:27 ericP, you wanted to say that unresolvable identifiers create issues 17:26:51 ericP: we can't calculate the same blank node twice 17:27:04 He just wants to distinguish between blank nodes 17:27:10 ... blank nodes are unpleasant in rdf 17:27:20 ... lack of commitment towards identifiers 17:27:41 +1 to eric 17:28:04 ... bnodes should be used for identifiers that you're not going to remember for future responses 17:28:11 http://www.w3.org/2001/sw/rdb2rdf/track/issues/raised 17:28:32 mhausenblas: how should we proceed with the issues? 17:28:42 juansequeda: let's go through them one by one, open them 17:28:54 mhausenblas: PROPSOAL: change ISSUE-9 to OPEN 17:29:14 I'd like the issue of use or non-use of bNodes to be raised as an issue so that we can discuss it later 17:29:16 soeren: rename it to "avoid blank nodes"? 17:29:18 +1 17:29:23 +1 17:29:25 +1 17:29:42 +1 17:29:56 s/PROPSOAL/PROPOSAL 17:30:10 PROPOSAL: change ISSUE-9 to OPEN 17:30:35 RESOLVED: change ISSUE-9 to OPEN 17:30:40 ISSUE-10? 17:30:41 ISSUE-10 -- Hash vs Slash -- raised 17:30:41 http://www.w3.org/2001/sw/rdb2rdf/track/issues/10 17:30:43 open 17:31:27 ericP: there's this linked data fury going on 17:31:43 ... long and contentious issue about uris 17:32:00 ... have an rdf file that has a node in it that identifies what you're talking about 17:32:18 ... and label that node with a relative hash URI 17:33:16 ... or alternative: don't use a hash, but just a slash URI, and a GET does http redirect to the file URI 17:33:36 q+ 17:33:36 ... one is clearer, one is simpler 17:33:47 ack ivan 17:34:20 ivan: i see direct graph as intermediate graph, where i use rules or something else to transform it into something i really like 17:34:21 q+ 17:34:38 ... that's my impression. might be rat hole 17:34:55 mhausenblas: let's not resolve issues now, but just open them 17:34:59 ack cygri 17:35:12 i think the distinguishing situation comes when there's a predicate which applies both to the record and the document describing the record 17:35:54 PROPOSAL: change ISSUE-10 to OPEN 17:35:57 +1 17:36:01 +1 17:36:07 +1 17:36:08 +1 17:36:11 RESOLVED: change ISSUE-10 to OPEN 17:36:13 +1 17:36:17 ISSUE-11? 17:36:17 ISSUE-11 -- Primary Key is a Candidate Key -- raised 17:36:17 http://www.w3.org/2001/sw/rdb2rdf/track/issues/11 17:37:04 q? 17:37:18 IMO "Common data modeling" should not be addressed by the Direct Mapping 17:38:31 FK is a PK? 17:39:09 juansequeda: this should read: "Primary Key is Foreign Key" 17:39:40 PROPOSAL: change ISSUE-11 to OPEN 17:39:42 +1 17:39:46 +1 17:39:48 +1 17:39:55 RESOLVED: change ISSUE-11 to OPEN 17:40:28 ACTION: Juan to rename Issue 11 and fix it in the DM 17:40:28 Created ACTION-98 - Rename Issue 11 and fix it in the DM [on Juan Sequeda - due 2011-02-08]. 17:40:49 ISSUE-12? 17:40:49 ISSUE-12 -- Hierarchical Tables -- raised 17:40:49 http://www.w3.org/2001/sw/rdb2rdf/track/issues/12 17:41:42 ericP: related to previous issue. first one is: what happens if pk is fk? second is: assuming we consider pk=fk a hierarchical table, then how do we model it? 17:41:47 q+ 17:42:04 ack cygri 17:43:48 PROPOSAL: change ISSUE-12 to POSTPONED 17:43:49 /me agrees to keep it somewhere, not opened 17:44:16 cygri: what does POSTPONED mean? 17:44:31 mhausenblas: we may discuss it again if someone comes with new information 17:44:47 +1 17:44:53 +1 17:44:55 +1 17:44:56 +1 17:44:59 RESOLVED: change ISSUE-12 to POSTPONED 17:45:00 cygri, would you propose that issue 11 be resolved as this?: primary keys which are also foreign keys are treated as if that foreign key doesn't exist 17:45:18 ISSUE-13? 17:45:18 ISSUE-13 -- Foreign Key and Primary Key rearrangement -- raised 17:45:18 http://www.w3.org/2001/sw/rdb2rdf/track/issues/13 17:45:18 (i have no problem with that) 17:46:14 ericP: this is again dependent on ISSUE-11 17:46:25 juansequeda: can we merge ISSUE-11, ISSUE-12, ISSUE-13 17:46:59 ivan: edit issues manually to add references between them 17:47:35 PROPOSAL: change ISSUE-13 to POSTPONED; add refs from ISSUE-11 to ISSUE-13 17:47:40 +1 17:47:46 +1 17:47:48 +1 17:47:49 +1 17:47:50 RESOLVED: change ISSUE-13 to POSTPONED; add refs from ISSUE-11 to ISSUE-13 17:48:21 ACTION: Juan to change ISSUE-13 to postponed and add ref from ISSUE-11 to ISSUE-13 17:48:21 Created ACTION-99 - Change ISSUE-13 to postponed and add ref from ISSUE-11 to ISSUE-13 [on Juan Sequeda - due 2011-02-08]. 17:48:30 ISSUE-14? 17:48:30 ISSUE-14 -- Many-to-Many tables -- raised 17:48:30 http://www.w3.org/2001/sw/rdb2rdf/track/issues/14 17:49:10 +1 17:49:11 PROPOSAL: change ISSUE-14 to POSTPONED 17:49:12 -1 17:49:14 q+ 17:49:15 -1 17:49:22 ack cygri 17:49:44 q+ 17:51:06 q+ 17:51:25 ack betehess 17:51:32 cygri: many to many tables are important 17:52:01 q+ 17:52:12 betehess: my objection is that the direct mapping should be kept really simple, just expose the relational model, simple expression of that in the RDF domain 17:52:22 q+ 17:52:35 ... if we do one case, then we have to do a lot of cases 17:52:40 q? 17:52:52 ack Ashok 17:53:19 ashok: i agree with keeping the direct mapping simple. q to richard: how do you figure out that something is many to many? 17:53:32 Ashok, you can identify some patterns, not all 17:53:36 ack juansequeda 17:53:43 juansequeda: i agree with everybody 17:53:48 ... let's keep it simple 17:54:12 ... we could have a direct mapping plus optional features 17:54:30 ... many to many is usually two-column table 17:54:53 ... that's how tools translate uml to sql ddl 17:55:00 ashok: what if extra columns? 17:55:01 another prob with a special case for binary relations is that not all such relations are MxN (e.g ConventiallyMarriedCouple(Wife, Husband)) 17:55:04 i think this should be an R2RML feature 17:55:11 juansequeda: then it's not a many to many 17:55:25 ericP, just like the hierarchical pattern? ;-) 17:55:25 PROPOSAL: change ISSUE-14 to OPEN 17:55:26 +1 17:55:27 +1 17:55:29 +1 17:55:31 +1 17:55:31 +1 17:55:34 +1 17:55:39 RESOLVED: change ISSUE-14 to OPEN 17:55:40 ISSUE-15? 17:55:40 ISSUE-15 -- Formalism -- raised 17:55:40 http://www.w3.org/2001/sw/rdb2rdf/track/issues/15 17:55:58 betehess, yeah, i'm totally game to ignore foreign keys which are also primary keys 17:56:24 juansequeda: this is an issue already written in the document 17:56:42 q+ 17:57:04 ack cygri 17:59:10 q+ 17:59:16 ack ivan 17:59:19 mhausenblas, did you say "either"? 17:59:50 mhausenblas: three options: datalog, set-based notation, plain english 18:00:09 ivan: the three options address different communities 18:00:15 ... having both in the document is viable 18:00:29 PROPOSAL: change ISSUE-15 to OPEN, and rephrase to highlight the three options (datalog, set-based notation, plain english) 18:01:19 I would say "consistent" 18:01:41 +1 18:01:44 +1 18:01:49 +1 18:01:54 +1 18:01:56 +1 18:01:56 +1 18:01:59 RESOLVED: change ISSUE-15 to OPEN, and rephrase to highlight the three options (datalog, set-based notation, plain english) 18:02:44 -Ashok_Malhotra 18:02:45 Adjourned 18:02:55 -Seema 18:02:59 -souri 18:03:00 -soeren 18:03:02 ericP, do you have a second? 18:03:02 zakim, drop me 18:03:02 Ivan is being disconnected 18:03:04 -Ivan 18:03:10 -boris 18:03:14 re the hierarchical table thing? 18:03:21 cygri, sure 18:03:38 -Alexandre 18:03:47 -dmcneil 18:07:18 RRSAgent, draft minutes 18:07:18 I have made the request to generate http://www.w3.org/2011/02/01-rdb2rdf-minutes.html mhausenblas 18:07:25 RRSAgent, make logs public 18:07:26 gotta go guys, have fun geeking off 18:07:31 -juansequeda 18:07:36 cheers, and thanks a lot juansequeda 18:09:49 ScribeOptions: -final, -noEmbedDiagnostics 18:09:54 RRSAgent, draft minutes 18:09:54 I have made the request to generate http://www.w3.org/2011/02/01-rdb2rdf-minutes.html mhausenblas 18:10:32 ScribeOptions: -final -noEmbedDiagnostics 18:10:35 RRSAgent, draft minutes 18:10:35 I have made the request to generate http://www.w3.org/2011/02/01-rdb2rdf-minutes.html mhausenblas 18:10:59 RRSAgent, draft minutes 18:10:59 I have made the request to generate http://www.w3.org/2011/02/01-rdb2rdf-minutes.html mhausenblas 18:11:31 ScribeOptions: -final -noEmbedDiagnostics 18:11:38 RRSAgent, draft minutes 18:11:38 I have made the request to generate http://www.w3.org/2011/02/01-rdb2rdf-minutes.html mhausenblas 18:11:55 RRSAgent, draft minutes 18:11:55 I have made the request to generate http://www.w3.org/2011/02/01-rdb2rdf-minutes.html mhausenblas 18:13:09 RRSAgent, draft minutes 18:13:09 I have made the request to generate http://www.w3.org/2011/02/01-rdb2rdf-minutes.html mhausenblas 18:17:00 trackbot, end telecon 18:17:00 Zakim, list attendees 18:17:00 As of this point the attendees have been boris, juansequeda, mhausenblas, +1.636.544.aaaa, Ashok_Malhotra, souri, +1.284.612.aabb, Alexandre, +1.603.891.aacc, Seema, EricP, 18:17:01 RRSAgent, please draft minutes 18:17:01 I have made the request to generate http://www.w3.org/2011/02/01-rdb2rdf-minutes.html trackbot 18:17:02 RRSAgent, bye 18:17:02 I see 2 open action items saved in http://www.w3.org/2011/02/01-rdb2rdf-actions.rdf : 18:17:02 ACTION: Juan to rename Issue 11 and fix it in the DM [1] 18:17:02 recorded in http://www.w3.org/2011/02/01-rdb2rdf-irc#T17-40-28 18:17:02 ACTION: Juan to change ISSUE-13 to postponed and add ref from ISSUE-11 to ISSUE-13 [2] 18:17:02 recorded in http://www.w3.org/2011/02/01-rdb2rdf-irc#T17-48-21 18:17:04 ... dmcneil, soeren, +886201aadd, Ivan, nunolopes