13:47:31 RRSAgent has joined #sparql 13:47:31 logging to http://www.w3.org/2009/08/11-sparql-irc 13:47:33 RRSAgent, make logs world 13:47:33 Zakim has joined #sparql 13:47:35 Zakim, this will be 77277 13:47:35 ok, trackbot; I see SW_(SPARQL)10:00AM scheduled to start in 13 minutes 13:47:36 Meeting: SPARQL Working Group Teleconference 13:47:36 Date: 11 August 2009 13:47:40 Zakim, this will be sparql 13:47:40 ok, LeeF; I see SW_(SPARQL)10:00AM scheduled to start in 13 minutes 13:47:42 Chair: LeeF 13:47:45 Scribe: SimonS 13:47:47 KjetilK has joined #sparql 13:47:47 Scribenick: SimonS 13:48:01 Regrets: IvanH, pgearon, AndyS 13:48:24 Agenda: http://www.w3.org/2009/sparql/wiki/Agenda-2009-08-11 13:48:30 LeeF has changed the topic to: Agenda - http://www.w3.org/2009/sparql/wiki/Agenda-2009-08-11 13:51:13 my connection's so good right now i'm considering using skype or vonage for the sparql call, instead of my cell phone 13:53:08 SimonS has joined #sparql 13:55:37 wow, people have been active while I have been away 13:56:46 don't you just hate when the world moves on while you're on holiday? :) 13:57:15 it's very depressing :) 13:58:12 SW_(SPARQL)10:00AM has now started 13:58:19 + +1.518.276.aaaa 13:58:20 +??P11 13:58:25 Zakim, aaaa is me 13:58:25 +kasei; got it 13:58:32 Zakim, mute me 13:58:36 kasei should now be muted 13:58:40 +LeeF 13:58:56 zakim, ??P11 is me 13:58:59 +LukeWM; got it 13:59:00 + +1.207.735.aabb 13:59:07 Zakim, aabb is me 13:59:07 +SteveH; got it 13:59:08 Zakim, ??P11 is me 13:59:08 I already had ??P11 as LukeWM, LukeWM 13:59:25 +??P17 13:59:38 Zakim, ??P17 is me 13:59:38 +SimonS; got it 14:00:04 +??P18 14:00:11 I'm clling from home, in london, it's noisy :) 14:00:13 so you'd know 14:00:15 Zakim. ??P18 is me 14:00:21 ok, cool 14:00:23 +??P20 14:00:25 Zakim, ??P20 is me 14:00:26 +AlexPassant; got it 14:00:52 zakim, who's on the phone? 14:00:53 On the phone I see kasei (muted), LukeWM, LeeF, SteveH, SimonS, ??P18, AlexPassant 14:01:05 +john-l 14:01:16 -LukeWM 14:01:17 -??P18 14:01:18 +AxelPolleres 14:01:44 +??P11 14:02:03 +??P18 14:02:03 Zakim. ??P11 is me 14:02:08 +??P31 14:02:19 bglimm has joined #SPARQL 14:02:20 Zakim, ??P31 is me 14:02:20 +LukeWM; got it 14:02:31 +bcuencagrau 14:02:32 chimezie has joined #sparql 14:02:35 zakim, ??P18 is Orri 14:02:35 +Orri; got it 14:02:38 Zakim, what is the passcode? 14:02:38 the conference code is 77277 (tel:+1.617.761.6200 tel:+33.4.89.06.34.99 tel:+44.117.370.6152), chimezie 14:02:47 Zakim, mute me 14:02:47 sorry, KjetilK, I do not know which phone connection belongs to you 14:02:48 Zakim, bcuencagrau is bglimm 14:02:50 +bglimm; got it 14:02:56 Zakim, who is talking 14:02:56 I don't understand 'who is talking', KjetilK 14:02:59 -SimonS 14:03:00 Zakim, who is talking? 14:03:07 zakim, ??P11 is kjetilk 14:03:07 +kjetilk; got it 14:03:10 KjetilK, listening for 10 seconds I heard sound from the following: 10 (28%), ??P11 (49%), LeeF (36%) 14:03:26 zakim, who's on the phone? 14:03:26 On the phone I see kasei (muted), LeeF, SteveH, AlexPassant, john-l, AxelPolleres, kjetilk, Orri, LukeWM, bglimm 14:03:31 Zakim, mute me 14:03:31 kjetilk should now be muted 14:03:32 +Chimezie_Ogbuji 14:03:33 +??P36 14:03:43 Zakim, ??P36 is me 14:03:43 +SimonS; got it 14:04:22 RRSAgent, please dial ericP-office 14:04:22 I'm logging. I don't understand 'please dial ericP-office', ericP. Try /msg RRSAgent help 14:04:30 +Prateek 14:04:40 + +212.21.280.3aacc 14:04:40 Zakim, please dial ericP-office 14:04:40 ok, ericP; the call is being made 14:04:41 +EricP 14:04:47 Zakim, mute me 14:04:47 Chimezie_Ogbuji should now be muted 14:04:49 Prateek has joined #sparql 14:05:33 +33.4.89.06.34.99 does not work, btw. 14:05:49 Hello 14:05:51 iv_an_ru, are you on the call? 14:06:06 yes, via UK number 14:06:20 zakim, aacc is iv_an_ru 14:06:20 +iv_an_ru; got it 14:06:23 zakim, who's here? 14:06:23 On the phone I see kasei (muted), LeeF, SteveH, AlexPassant, john-l, AxelPolleres, kjetilk (muted), Orri, LukeWM, bglimm, Chimezie_Ogbuji (muted), SimonS, Prateek, iv_an_ru, EricP 14:06:26 On IRC I see Prateek, chimezie, bglimm, SimonS, KjetilK, Zakim, RRSAgent, LukeWM, AxelPolleres, SteveH, LeeF, karl, john-l, iv_an_ru, kjetil, AlexPassant, trackbot, kasei, ericP 14:07:00 LeeF: Topics for today are Aggregate design and discovering service descriptions 14:07:23 topic: admin 14:07:30 PROPOSED: Approve minutes at http://www.w3.org/2009/sparql/meeting/2009-08-04 14:07:53 +1 14:08:07 RESOLVED: Approve minutes at http://www.w3.org/2009/sparql/meeting/2009-08-04 14:08:27 Next meeting: 2009-08-18 @ 15:00 BST / 10:00 EDT, SimonKJ to scribe 14:08:34 Next week I am on holiday 14:08:41 http://www.w3.org/2009/sparql/wiki/Vacation_List 14:08:51 regrets next week: bglimm, orri 14:09:42 wiki page for next F2F http://www.w3.org/2009/sparql/wiki/F2F2 14:10:08 LeeF: F2F 1st week of November in Santa Clara. 14:10:09 $50/day 14:10:52 ... Please indicate your attendance on the Wiki 14:11:10 Zakim, unmute me 14:11:10 Chimezie_Ogbuji should no longer be muted 14:11:29 q+ 14:11:29 Good question, I don't know off head (will need to chew on that). 14:11:37 whoops 14:11:50 LeeF: SPARQL group meeting Monday and Tuesday. 14:12:06 ack me 14:12:12 ack kjetilk 14:12:31 KletilK: how about a split meeting with video conferencing? 14:12:36 +1 to KjetilK 14:12:39 q+ to talk about challenges 14:12:44 q- 14:12:53 q+ to talk about tech challenges re: vid conf 14:13:05 LeeF: might be possible, but huge time difference, European side needs to how night owls. 14:13:13 s/how/host/ 14:13:36 I would fly just for the 2 days and the jet-lag would kill me, I rather stay up late here 14:13:45 Zakim, mute me 14:13:45 kjetilk should now be muted 14:13:53 I could probably organize some video conferencing here 14:14:47 EricP: point of the meeting also is to interact with other groups, which means we need video conferencing on site, which is prohibitively expensive. 14:15:05 LeeF: Unlikely that we will have video conferencing. 14:15:19 ... phone will be available, though. 14:15:57 can we chivvy people to say whether they're going or not? 14:16:03 I have to decide soon 14:16:09 Which Ivan? 14:16:13 nothing new from HCLS or XQuery 14:16:15 topic: Liaisons 14:17:01 Orri: nothing new from RDB2RDF 14:17:14 no news from RIF (teleconfs irregular, there is one today, so I will know more next week) 14:17:35 Orri: talk about it at the F2F. 14:17:39 open actions - http://www.w3.org/2009/sparql/track/actions/open 14:17:42 topic: actions 14:17:52 trackbot, close ACTION-66 14:17:52 ACTION-66 Draft aggregates closed 14:20:07 topic: Aggregates 14:20:09 71 is done from my side in the sense that rif and rdb2rdf are informed. 14:20:24 draft of aggregate design at http://www.w3.org/2009/sparql/wiki/Design:Aggregate 14:21:29 chimezie: First draft, some issues regarding sets vs multi-sets 14:21:39 ... do we need specific restrictions? 14:21:48 ... how to deal with DISTINCT? 14:21:55 open issues at http://www.w3.org/2009/sparql/wiki/Design:Aggregate#Status 14:22:22 ... seems we want to have variables associated with result of aggregates, so we always need AS 14:22:44 ... tried to describe algebra extension. 14:23:20 ... Start with groups function 14:23:56 ... starting with grouped variables. 14:24:39 ... function partitions takes solution set and extracts unique n-tuples, which are partitions of the solution set 14:24:51 q+ to ask about whether bnodes should be considered nasty or not 14:25:15 ack ericp 14:25:16 ericP, you wanted to talk about tech challenges re: vid conf 14:25:20 ... Aggregation then computes the actual aggregate. 14:25:29 ... now need test cases 14:26:21 ack me 14:26:21 AxelPolleres, you wanted to ask about whether bnodes should be considered nasty or not 14:26:59 q+ to propose we stay with a graph semantics 14:27:02 AxelPolleres: Are BNodes in the solution set an issue? e.g. count is difficult, if BNodes are treated as existentials 14:27:13 ... most implementations treat them as constants, though. 14:27:56 I agrre in that blank nodes in our reasoner (OWL direct semantics) are not the same as constants 14:28:00 Orri: We treat them as constants, sometimes owl:sameAs semantics is applied 14:28:06 ack ericP 14:28:06 ericP, you wanted to propose we stay with a graph semantics 14:28:26 EricP: Language should stay a graph based language. 14:28:31 similar with "!=" which is currently "not known to be equal" 14:29:14 LeeF: treat as in equals in filters 14:29:25 ... might need to look at this again for entailment regimes. 14:29:38 ISSUE: How do other entailment regimes interact with aggregate grouping vis a vis blank nodes? 14:29:38 Created ISSUE-34 - How do other entailment regimes interact with aggregate grouping vis a vis blank nodes? ; please complete additional details at http://www.w3.org/2009/sparql/track/issues/34/edit . 14:30:25 Orri: Guess, you can do expressions of aggregates 14:31:46 for the record, extensibility of aggregate functions is an open issue http://www.w3.org/2009/sparql/track/issues/15 14:31:48 ... are user defined aggregates in scope, but we might need syntax restrictions? 14:32:18 LeeF: we already have issue for extensions in aggregate functions 14:32:22 am fiddling with grammar (has S/R errors) -- http://www.w3.org/2005/01/yacker/uploads/SPARQL_Aggregate?lang=perl 14:32:22 -SimonS 14:32:59 +??P30 14:33:08 Zakim, ??P30 is me 14:33:08 +SimonS; got it 14:33:46 LeeF: can aggregate functions take multiple arguments? 14:34:00 Chimezie: As long as all variables are part of gorup keys, should be ok, not sure if SQL aggregate functions do this at all 14:34:05 Orri: there are a few like diverse_regression 14:34:37 ok, no S/Rs in http://www.w3.org/2005/01/yacker?name=SPARQL_Aggregate&replace=1&lang=perl 14:35:11 chimezie; issues with multi sets. Do not require uniqueness. however, Aggregates do for partitioning. 14:35:49 EricP: Algebra does not have ordering, but aggregates need them. Current algebra should work. 14:35:58 Orri: Why do aggregates require ordering? 14:36:09 EricP: Not always, but might make sense. 14:36:28 SteveH did have an example on this SubSelect design wiki asking about ordering and aggregation (working together) 14:36:35 s/this/the 14:36:35 Orri: For user defined aggregates we have a flag for that, but usually it is not neccessary. 14:36:58 ... should not be an issue, if we do not specify extension syntax 14:37:18 q? 14:37:35 iv_an_ru: also benefits for parallelization then. 14:37:51 Zakim, who is here? 14:37:51 On the phone I see kasei (muted), LeeF, SteveH, AlexPassant, john-l, AxelPolleres, kjetilk (muted), Orri, LukeWM, bglimm, Chimezie_Ogbuji, Prateek, iv_an_ru, EricP, SimonS 14:37:55 On IRC I see Prateek, chimezie, bglimm, SimonS, KjetilK, Zakim, RRSAgent, LukeWM, AxelPolleres, SteveH, LeeF, karl, john-l, iv_an_ru, kjetil, AlexPassant, trackbot, kasei, ericP 14:38:20 LeeF: do we need test case, that needs ordering? 14:38:30 EricP: same as for SubSelect. 14:38:48 LeeF: Last week we had consensus to discard ordering for subqueries. 14:39:12 Orri: ORDER BY allowed? 14:39:37 LeeF: yes, needed for slicing for example, but when combined with parent query, order is lost. 14:40:07 LeeF: what specific aggregate functions to include? 14:40:10 any slicing in subqueries potentially introduces non-determinism, but well, I guess that was discussed? 14:40:17 ... discuss tios on the mailing list. 14:40:19 chimezie, do you know of a grammar proposal for SELECT ?foo AS ?bar which i could inject tinot the SPARQL_Aggregate grammar? 14:40:46 LeeF: How to apply REDUCED / DISTINCT? Afterwards? 14:41:04 chimezie: if done afterwards, everything should be fine. 14:41:05 ahh, it was in your proposal 14:41:14 Orri: grouped columns are distinct anyway. 14:42:01 Orri: Can we have DISTINCT in aggregate expressions? 14:42:16 ... e.g. SELECT COUNT(DISTINCT ?X) 14:42:33 ISSUE: Can aggregate functions take DISTINCT as an argument a la SELECT COUNT(DISTINCT ?X)? 14:42:33 Created ISSUE-35 - Can aggregate functions take DISTINCT as an argument a la SELECT COUNT(DISTINCT ?X)? ; please complete additional details at http://www.w3.org/2009/sparql/track/issues/35/edit . 14:42:55 q+ to ask about HAVING 14:43:13 ack LukeWM 14:43:13 LukeWM, you wanted to ask about HAVING 14:43:34 LukeWM: does HAVING cause issues? 14:43:43 Orri: HAVING is save. 14:44:02 ... can be done in nested query. 14:44:06 q? 14:44:43 we had talked earlier about using FILTER instead of HAVING (not introducing new terms for roughly the same thing) 14:44:53 yes, reusing FILTER would makesense 14:45:06 chimezie: should be easy to add to the proposal for completeness' sake. 14:45:46 ACTION: Chimezie to continue forward with aggregates w.r.t test cases, HAVING/FILTER clause, ISSUE-35, ... 14:45:46 Created ACTION-79 - Continue forward with aggregates w.r.t test cases, HAVING/FILTER clause, ISSUE-35, ... [on Chimezie Ogbuji - due 2009-08-18]. 14:46:23 topic: service description 14:47:22 -> http://lists.w3.org/Archives/Public/public-rdf-dawg/2009JulSep/0139.html 14:47:26 LeeF: Most important question is discovery mechanism. We hava >= 8 proposals. 14:47:42 s/hava/have/ 14:48:54 ... drop proposal 3 - Well known location. 14:49:02 ... general agreement on this. 14:49:23 ... drop 5 - Query as well. 14:49:31 is "DESCRIBE <.>" also meant as a suboption of Opt 4? 14:49:42 ... EricP likes it, but noone else. 14:50:32 ... some objections to 6: prefer discovery via the endpoint instead of via the query. 14:52:07 chimezie, http://tinyurl.com/SPARQL-sum shows that your example query works with the grammar you supplied (modulo AggregateFunc which I added) 14:52:16 ... issue with option 7 without conneg is that existing implementations might have webpages at endpoint URI 14:52:38 ... proposal 8: do get with some special operation 14:52:43 ericP: thanks 14:53:00 feel free to fiddle with the grammar 14:53:10 (note [Edit this grammar]) 14:53:11 ... is anyone NOT happy with using an approach based on the endpoint rather than the query? 14:53:18 eh 14:53:56 Zakim, unmute me 14:53:56 kasei should no longer be muted 14:54:10 EricP: might be nice to be able to query endpoint descriptions, but could solve that differently. 14:54:46 q+ 14:54:47 LukeWM: favors conneg 14:54:53 s/LukeWM/kasei 14:55:08 np 14:55:17 Zakim, mute me 14:55:17 kasei should now be muted 14:55:21 ack AxelPolleres 14:55:34 AxelPolleres: What was objection to option 4? 14:55:53 LeeF: restricts possible datasets and URIs 14:55:59 and that describe doesn't always return the same things... 14:56:02 q+ to ask how i find for instance, what VoID description it has in opt 4 14:56:21 LeeF: same for DESCRIBE <> as it is just a shortcut 14:56:28 ack ericP 14:56:28 ericP, you wanted to ask how i find for instance, what VoID description it has in opt 4 14:57:12 you can still do FROM .... on stores that support it 14:57:13 EricP: that also means optimization becomes more difficult than just serving a void description. 14:57:39 Orri: You would usually ask for the whole graph once. 14:58:20 EricP: imagine void, void* etc, so guessing the best representation is a burden on the endpoint 14:59:36 Orri: don't want to do many round trips with lots of short queries. Retrieve full description once, then do postprocessing locally. 14:59:59 EricP: But we might be interested in certain aspects of the description only. 15:00:09 q+ to ask about the relative or absolute description in the protocol based options 15:00:22 ericP's point, I think, supports conneg or a simple GET mechanism so that you *could* point a SPARQL query at the SD if you wanted. 15:00:24 zakim, close the queue 15:00:24 ok, LeeF, the speaker queue is closed 15:01:01 Orri: We might say in the viod description that the description is queryable, and where. 15:01:07 s/viod/void/ 15:01:24 ack AxelPolleres 15:01:24 AxelPolleres, you wanted to ask about the relative or absolute description in the protocol based options 15:02:07 AxelPolleres: option 1 is just about returning a link to the service description, i.e. two GETs are neccessary, while the others are one GET only. 15:02:13 LeeF: that is right. 15:02:32 2 GETs for getting to the service description seems a bit awkward to me, personally. 15:02:59 PROPOSED: Service description discovery should be based on an operation performed against a SPARQL endpoint, ruling out options 3,4,5,6 in http://lists.w3.org/Archives/Public/public-rdf-dawg/2009JulSep/0139.html 15:03:51 need to get something clear: does it mean we agree that QUERYING the service description should NOT necessarily be allowed on the very endpoint? 15:04:02 -iv_an_ru 15:04:22 I'd say not required. 15:04:43 to be convinced I'd need to be shown that it works, not that it meets some usecases 15:05:03 EricP: Could do use cases for querying. Would that be worth while? 15:05:13 you can still do FROM .... on stores that support it 15:05:30 Orri: Propose to include in the endpoint based description link to the queryable version 15:06:18 option 7 gives you queryability for free with a FROM clause. 15:07:03 LeeF: discussion closed, please continue on the mailing list. Continue discussion next week 15:07:10 ACTION: Orri to send a compromise proposal to the mailing list 15:07:11 Created ACTION-80 - Send a compromise proposal to the mailing list [on Orri Erling - due 2009-08-18]. 15:07:44 -Chimezie_Ogbuji 15:07:44 Adjourned. 15:07:46 -AxelPolleres 15:07:53 bye 15:07:55 -Orri 15:07:56 bye 15:07:57 -EricP 15:07:57 -john-l 15:07:58 -bglimm 15:07:59 -AlexPassant 15:08:00 -Prateek 15:08:00 -SteveH 15:08:02 -LukeWM 15:08:06 -kjetilk 15:08:10 -kasei 15:08:20 http://lists.w3.org/Archives/Public/public-rdf-dawg/2009AprJun/0406.html 15:08:26 (how to do the minutes) 15:08:39 -LeeF 15:08:47 -SimonS 15:08:51 SW_(SPARQL)10:00AM has ended 15:08:52 Attendees were +1.518.276.aaaa, kasei, LeeF, LukeWM, +1.207.735.aabb, SteveH, SimonS, AlexPassant, john-l, AxelPolleres, Orri, bglimm, kjetilk, Chimezie_Ogbuji, Prateek, 15:08:54 ... +212.21.280.3aacc, EricP, iv_an_ru 15:26:44 minutes are available at http://www.w3.org/2009/sparql/meeting/2009-08-11 15:26:48 bye 15:26:51 SimonS has left #sparql 15:28:16 AxelPolleres has left #sparql 15:31:06 AxelPolleres has joined #sparql 17:24:48 Zakim has left #sparql