SPARQL Working Group

Minutes of 10 March 2009

Regrets

Bijan Parsia

Chair

Lee Feigenbaum

Scribe

Phil Brooks

IRC Log

Original and Editable Wiki Version

Resolutions

1. Approve minutes at http://www.w3.org/2009/03/03-sparql-minutes.html link

Topics

1. Administrivia

2. next meeting

3. Face to Face

4. overview of features

5. ProjectExpressions

   initial straw poll gives (+/0/-): 13/3/0

6. subselects

   initial straw poll gives (+/0/-): 8/8/1

13:47:53 <RRSAgent> RRSAgent has joined #sparql

RRSAgent IRC Bot: RRSAgent has joined #sparql ←

13:47:53 <RRSAgent> logging to http://www.w3.org/2009/03/10-sparql-irc

RRSAgent IRC Bot: logging to http://www.w3.org/2009/03/10-sparql-irc ←

13:48:09 <LeeF> zakim, this will be SPARQL

Lee Feigenbaum: zakim, this will be SPARQL ←

13:48:09 <Zakim> ok, LeeF; I see SW_(SPARQL)10:00AM scheduled to start in 12 minutes

Zakim IRC Bot: ok, LeeF; I see SW_(SPARQL)10:00AM scheduled to start in 12 minutes ←

13:48:13 <LeeF> zakim, code?

Lee Feigenbaum: zakim, code? ←

13:48:13 <Zakim> the conference code is 77277 (tel:+1.617.761.6200 tel:+33.4.89.06.34.99 tel:+44.117.370.6152), LeeF

Zakim IRC Bot: the conference code is 77277 (tel:+1.617.761.6200 tel:+33.4.89.06.34.99 tel:+44.117.370.6152), LeeF ←

13:48:41 <LeeF> rrsagent, draft minutes

Lee Feigenbaum: rrsagent, draft minutes ←

13:48:41 <RRSAgent> I have made the request to generate http://www.w3.org/2009/03/10-sparql-minutes.html LeeF

RRSAgent IRC Bot: I have made the request to generate http://www.w3.org/2009/03/10-sparql-minutes.html LeeF ←

13:48:47 <LeeF> rrsagent, makes minutes world

Lee Feigenbaum: rrsagent, makes minutes world ←

13:48:47 <RRSAgent> I'm logging. I don't understand 'makes minutes world', LeeF.  Try /msg RRSAgent help

RRSAgent IRC Bot: I'm logging. I don't understand 'makes minutes world', LeeF. Try /msg RRSAgent help ←

13:48:50 <LeeF> rrsagent, makes log world

Lee Feigenbaum: rrsagent, makes log world ←

13:48:50 <RRSAgent> I'm logging. I don't understand 'makes log world', LeeF.  Try /msg RRSAgent help

RRSAgent IRC Bot: I'm logging. I don't understand 'makes log world', LeeF. Try /msg RRSAgent help ←

13:48:53 <LeeF> rrsagent, make log world

Lee Feigenbaum: rrsagent, make log world ←

13:49:13 <LeeF> Regrets: Bijan

13:49:47 <LeeF> Chair: LeeF

13:49:51 <LeeF> Scribe: Phil Brooks

(Scribe set to Phil Brooks)

13:50:58 <LeeF>  Agenda: http://www.w3.org/2009/sparql/wiki/Agenda-2009-03-10

Lee Feigenbaum: Agenda: http://www.w3.org/2009/sparql/wiki/Agenda-2009-03-10 ←

13:52:02 <SteveH> SteveH has joined #sparql

Steve Harris: SteveH has joined #sparql ←

13:52:05 <kasei> kasei has joined #sparql

Greg Williams: kasei has joined #sparql ←

14:08:27 <LeeF> Scribenick: Phil

14:08:43 <LeeF> topic: Administrivia

(No events recorded for 16 minutes)

14:08:57 <LeeF> PROPOSED: Approve minutes at http://www.w3.org/2009/03/03-sparql-minutes.html

PROPOSED: Approve minutes at http://www.w3.org/2009/03/03-sparql-minutes.html ←

14:09:17 <LeeF> RESOLVED: Approve minutes at http://www.w3.org/2009/03/03-sparql-minutes.html

RESOLVED: Approve minutes at http://www.w3.org/2009/03/03-sparql-minutes.html ←

14:09:18 <Phil> Minutes from last week approved.

Minutes from last week approved. ←

14:09:30 <ivanh> topic: next meeting

14:09:49 <Souri> Souri has joined #sparql

Souri Das: Souri has joined #sparql ←

14:10:05 <Phil> Next Meeting: 10:00am EDT on March 17

Next Meeting: 10:00am EDT on March 17 ←

14:10:39 <LeeF> topic: Face to Face

14:11:02 <LeeF> -> http://www.w3.org/2009/sparql/wiki/F2F1 Face to Face wiki page

Lee Feigenbaum: -> http://www.w3.org/2009/sparql/wiki/F2F1 Face to Face wiki page ←

14:11:47 <ivanh> q+

Ivan Herman: q+ ←

14:12:31 <ericP> q+ to talk about sponsorship

Eric Prud'hommeaux: q+ to talk about sponsorship ←

14:12:45 <ywang4> it seems i could not login the wiki with my w3c account...

Yimin Wang: it seems i could not login the wiki with my w3c account... ←

14:13:02 <AxelPolleres> +1 to have standard setup for "normal" dial-in as well.

Axel Polleres: +1 to have standard setup for "normal" dial-in as well. ←

14:13:08 <LeeF> ywang4, I'll ask the Wiki Folks about it

Lee Feigenbaum: ywang4, I'll ask the Wiki Folks about it ←

14:13:15 <ywang4> thanks

Yimin Wang: thanks ←

14:13:17 <Phil> F2F scheduled from May 6-7.  In person attendance encouraged.  Everyone should check their calendars and let Lee know who will be attending (for planning purposes).

F2F scheduled from May 6-7. In person attendance encouraged. Everyone should check their calendars and let Lee know who will be attending (for planning purposes). ←

14:13:31 <LeeF> queue=

Lee Feigenbaum: queue= ←

14:13:58 <Phil> Cost at MIT is $20/day.  Looking for sponsors for the MIT site.

Cost at MIT is $20/day. Looking for sponsors for the MIT site. ←

14:14:25 <Phil> Parties interested in sponsoring the MIT site should contact Eric.

Parties interested in sponsoring the MIT site should contact Eric. ←

14:14:34 <Phil> (cheap advertising!)   :-)

(cheap advertising!) :-) ←

14:15:07 <AxelPolleres> ... two options for alternate location: Brussels(?) and Manchester.

Axel Polleres: ... two options for alternate location: Brussels(?) and Manchester. ←

14:15:34 <AndyS> Bristol

Andy Seaborne: Bristol ←

14:16:00 <AxelPolleres> s/Brussels(?)/Bristol/

Axel Polleres: s/Brussels(?)/Bristol/ ←

14:16:14 <ivanh> q+

Ivan Herman: q+ ←

14:16:20 <LeeF> ack iva

Lee Feigenbaum: ack iva ←

14:16:21 <LeeF> ack ivan

Lee Feigenbaum: ack ivan ←

14:16:30 <Phil> Opportunity for 2nd F2F at TPAC2009 in Santa Clara, CA the week of Nov. 2-6, 2009.  What does everyone think?

Opportunity for 2nd F2F at TPAC2009 in Santa Clara, CA the week of Nov. 2-6, 2009. What does everyone think? ←

14:17:18 <Phil> IvanH: Santa Clara may be too expensive.  W3C considering alternate location - will decide in several weeks.

Ivan Herman: Santa Clara may be too expensive. W3C considering alternate location - will decide in several weeks. ←

14:17:45 <iv_an_ru> For me, CA in Nov would be nice contrast with Novosibirsk in Nov :)

Ivan Mikhailov: For me, CA in Nov would be nice contrast with Novosibirsk in Nov :) ←

14:18:55 <Phil> ISWC is week before TPAC2009; attending both could be problematic/costly

ISWC is week before TPAC2009; attending both could be problematic/costly ←

14:19:34 <Phil> ISWC is Oct. 25-29

ISWC is Oct. 25-29 ←

14:19:41 <AxelPolleres> co-location with ISWC would be an option.

Axel Polleres: co-location with ISWC would be an option. ←

14:19:42 <ericP> ISWC2009 is 25-29 October per http://iswc2009.semanticweb.org/

Eric Prud'hommeaux: ISWC2009 is 25-29 October per http://iswc2009.semanticweb.org/ ←

14:19:44 <Phil> Alternately, F2F could occur at ISWC

Alternately, F2F could occur at ISWC ←

14:21:57 <Phil> TPAC may be a better option as there will be opportunity to integrate with other W3C groups.

TPAC may be a better option as there will be opportunity to integrate with other W3C groups. ←

14:25:37 <ivanh> Topic: overview of features

14:22:19 <LeeF> -> http://www.w3.org/2009/sparql/wiki/Category:Features feature prpodsals

Lee Feigenbaum: -> http://www.w3.org/2009/sparql/wiki/Category:Features feature prpodsals ←

14:24:16 <ericP> i wonder if we could use chad for rating the priorities

Eric Prud'hommeaux: i wonder if we could use chad for rating the priorities ←

14:25:17 <Phil> Lee and Axel's role is to ensure that the "right" list of features is adopted (i.e. Lee wants to make everyone unhappy - at least, a little!)

Lee and Axel's role is to ensure that the "right" list of features is adopted (i.e. Lee wants to make everyone unhappy - at least, a little!) ←

14:26:35 <Phil> Lee reminds that the group is responsible for creating the specifications for the features that are adopted (and that is not trivial).

Lee reminds that the group is responsible for creating the specifications for the features that are adopted (and that is not trivial). ←

14:27:16 <AxelPolleres> Lee: Point 1: We won't probably be able to do all in 18month, that might guide us to narrow down the number.

Lee Feigenbaum: Point 1: We won't probably be able to do all in 18month, that might guide us to narrow down the number. [ Scribe Assist by Axel Polleres ] ←

14:29:28 <AxelPolleres> Lee: Support by implementations important, pervasive support, usefulness. Can requested features be done with the language as is?

Lee Feigenbaum: Support by implementations important, pervasive support, usefulness. Can requested features be done with the language as is? [ Scribe Assist by Axel Polleres ] ←

14:29:34 <AndyS> Lee: Point 3: SPARQL already has some extension points

Lee Feigenbaum: Point 3: SPARQL already has some extension points [ Scribe Assist by Andy Seaborne ] ←

14:30:04 <AxelPolleres> Lee: option: standardize on extensibility points rather than extensions themselves.

Lee Feigenbaum: option: standardize on extensibility points rather than extensions themselves. [ Scribe Assist by Axel Polleres ] ←

14:30:47 <AndyS> Lee: Framework for features to converge outside of this WG process

Lee Feigenbaum: Framework for features to converge outside of this WG process [ Scribe Assist by Andy Seaborne ] ←

14:30:52 <Phil> Lee: The features that get adopted must be interoperable (and should be core to the language).  SPARQL v1 already has some extensibility points; just because we "could" standardize an extension does not mean we "have to".  It may be a better use of our time to standardize on extensibility points rather than to standardize an extension in and of itself.  For example, standardizing a service option may advance SPARQL further (especially with respect to interoperabilit

Lee Feigenbaum: The features that get adopted must be interoperable (and should be core to the language). SPARQL v1 already has some extensibility points; just because we "could" standardize an extension does not mean we "have to". It may be a better use of our time to standardize on extensibility points rather than to standardize an extension in and of itself. For example, standardizing a service option may advance SPARQL further (especially with respect to interoperabilit ←

14:32:36 <Zakim> -ywang4

Zakim IRC Bot: -ywang4 ←

14:32:47 <Zakim> +ywang4

Zakim IRC Bot: +ywang4 ←

14:33:38 <Phil> Lee: It's unrealistic to review all the proposed features on a teleconference; participation on the SPARQL working group must include work outside of the call.  In particular, please start threads on the mailing list regarding your "favorite" feature and why.  Others should reply to the posts, ask questions, clarify as needed, challenge as desired, etc.  In summary, the mailing lists (and associated threads) will be the main method for discussing the various feature

Lee Feigenbaum: It's unrealistic to review all the proposed features on a teleconference; participation on the SPARQL working group must include work outside of the call. In particular, please start threads on the mailing list regarding your "favorite" feature and why. Others should reply to the posts, ask questions, clarify as needed, challenge as desired, etc. In summary, the mailing lists (and associated threads) will be the main method for discussing the various feature ←

14:33:43 <ericP> q+ to suggest a mailing convention like Subject: [AccessingRdfLists] blah blah blah

Eric Prud'hommeaux: q+ to suggest a mailing convention like Subject: [AccessingRdfLists] blah blah blah ←

14:34:16 <LeeF> ack ericP

Lee Feigenbaum: ack ericP ←

14:34:16 <Zakim> ericP, you wanted to suggest a mailing convention like Subject: [AccessingRdfLists] blah blah blah

Zakim IRC Bot: ericP, you wanted to suggest a mailing convention like Subject: [AccessingRdfLists] blah blah blah ←

14:34:35 <ivanh> q+

Ivan Herman: q+ ←

14:34:45 <LeeF> ack ivan

Lee Feigenbaum: ack ivan ←

14:34:56 <AxelPolleres> +1 to distinct mail-subjects

Axel Polleres: +1 to distinct mail-subjects ←

14:34:56 <iv_an_ru> There are two features: BI and Federation. Others are minor details of these two :)

Ivan Mikhailov: There are two features: BI and Federation. Others are minor details of these two :) ←

14:35:12 <chimezie> There definately seems to be some overlap

Chime Ogbuji: There definately seems to be some overlap ←

14:35:37 <AxelPolleres> +1 to offline go over the list and try to propose merge to authors.

Axel Polleres: +1 to offline go over the list and try to propose merge to authors. ←

14:35:48 <Phil> There may be some features that could be merged - Lee encourages anyone interested in doing so to review which are candidates for merging and then make such a proposal.

There may be some features that could be merged - Lee encourages anyone interested in doing so to review which are candidates for merging and then make such a proposal. ←

14:36:02 <AxelPolleres> q+

Axel Polleres: q+ ←

14:37:04 <LeeF> ack AxelPolleres

Lee Feigenbaum: ack AxelPolleres ←

14:37:45 <Phil> Lee: All work group participants come from varying backgrounds and with different opinions - we will try to reach consensus.  However, we all need to maintain an open mind as we review the features and consider which ones to go forward with.

Lee Feigenbaum: All work group participants come from varying backgrounds and with different opinions - we will try to reach consensus. However, we all need to maintain an open mind as we review the features and consider which ones to go forward with. ←

14:38:54 <iv_an_ru> First we should agree about some objectives that are more precise than "better SPARQL, upward-compatible"

Ivan Mikhailov: First we should agree about some objectives that are more precise than "better SPARQL, upward-compatible" ←

14:38:59 <AxelPolleres> SteveH, ok that overconsolidation should be avoided, but try to make links *and differences* with related features explicit.

Axel Polleres: SteveH, ok that overconsolidation should be avoided, but try to make links *and differences* with related features explicit. ←

14:39:43 <ericP> as of last night, my top priorities were update and lists

Eric Prud'hommeaux: as of last night, my top priorities were update and lists ←

14:40:02 <LeeF> topic: ProjectExpressions

<LeeF> summary: initial straw poll gives (+/0/-): 13/3/0

14:40:05 <LeeF> -> http://www.w3.org/2009/sparql/wiki/Feature:ProjectExpressions

14:41:15 <ivanh> q+

14:42:06 <AndyS> I would relate it to constructors for RDF terms.

14:42:08 <LeeF> ack ivan

14:42:34 <chimezie> i think it returns a boolean

14:43:09 <chimezie> pure post-processing

14:43:14 <Phil> Ivan asked clarifying question about first example - the "(?age > 18)" projects a boolean value

14:44:08 <AxelPolleres> q+

14:44:08 <LeeF> zakim, who's here?

14:44:09 <Zakim> On the phone I see LukeWM, AndyS, john-l (muted), kasei (muted), Lee_Feigenbaum, iv_an_ru, Ivan, AxelPolleres, AlexPassant, SteveH, EricP, kjetil (muted), Orri, Phil,

14:44:12 <SteveH> sorry, it's a wacky first example

14:44:13 <Zakim> ... Chimezie_Ogbuji, DaveNewman, Souri, ywang4

14:44:14 <Zakim> On IRC I see Souri, ywang4, chimezie, Phil, AlexPassant, kasei, SteveH, RRSAgent, Zakim, AndyS, AxelPolleres, john-l, LukeWM, ivan, AndyS_, iv_an_ru, LeeF, sandro, kjetil,

14:44:16 <ivanh> q+

14:44:17 <Zakim> ... trackbot, ericP

14:44:17 <SteveH> mea culpa

14:44:29 <john-l> No, I think it's a fine first example, once you understand what's going on.

14:44:43 <LeeF> AxelPolleres: Might be one or the other with assignment

14:44:56 <ericP> i agree, and assignment is more powerful

14:44:57 <LeeF> ack ivan

14:45:00 <LeeF> ack AxelPolleres

14:45:04 <AxelPolleres> q-

14:45:04 <iv_an_ru> +q

14:45:29 <LeeF> ack iv_an_ru

14:45:32 <Phil> Lee: Syntax debates should be reserved for the mailing list

14:45:40 <john-l> Perhaps say "whether the person is over 18" instead of "where the person is over 18"?

14:47:20 <Souri> +1

14:47:28 <john-l> +0

14:47:28 <SteveH> +1

14:47:31 <ericP> +0

14:47:34 <Phil> Polling of opinions regarding Project Expressions (poll on IRC)

14:47:37 <AlexPassant> +1

14:47:38 <Phil> +1

14:47:39 <ivanh> +1

14:47:39 <kjetil> +0

14:47:40 <kasei> +1

14:47:40 <AxelPolleres> +1 (modulo redundancy avoidance w.r.t. assignment)

14:47:40 <ywang4> +1

14:47:41 <LukeWM> +1

14:47:46 <iv_an_ru> +1

14:47:50 <chimezie> +1

14:47:56 <AndyS> +1

14:47:58 <kasei> and agree with AndyS regarding the potential for rewriting

14:48:07 <LeeF> +1

14:49:14 <Phil> In general, the group seems to be strongly in favor of Project Expressions.

14:49:19 <LeeF> topic: subselects

<LeeF> summary: initial straw poll gives (+/0/-): 8/8/1

14:49:21 <LeeF> -> http://www.w3.org/2009/sparql/wiki/Feature:SubSelects

14:49:26 <Phil> Next topic: subselects

14:50:04 <LeeF> SteveH: subselects gives you other features "for free"

14:50:15 <LeeF> ... e.g. !ASK for some forms of negation

14:50:35 <ericP> q+ to say point out that unlike SQL, we've not needed subselects so far for e.g. coherent OPTIONALS (outer joins) and UNIONS.

14:51:08 <ivanh> q+

14:51:20 <Phil> In addition to Virtuoso as listed on the Wiki, there are other implementers of sub-select as well.

14:51:37 <LeeF> ack ericP

14:51:37 <Zakim> ericP, you wanted to say point out that unlike SQL, we've not needed subselects so far for e.g. coherent OPTIONALS (outer joins) and UNIONS.

14:51:38 <Phil> (at least 2, anyway)

14:52:17 <chimezie> +q to suggest we consider restricted subselects rather than all or nothing

14:52:53 <AndyS> The cost to the algebra is actually quite small to allow nesting queries.  One issue: breaks the multiset/sequence distinction but it's fixable and probably needed any way

14:52:57 <LeeF> ack ivan

14:53:00 <SteveH> q+ to disagree with eric

14:53:01 <ivanh> ?supp+>tpcd:acctbal

14:53:10 <AndyS> Related to: EXISTS/NOT EXISTS/UNSAID

14:53:19 <AndyS> which are a sub-ASK

14:55:24 <Souri> What does "+>" in ?supp+>tpcd:acctbal stand for?

14:56:01 <AxelPolleres> Is +> doable with braketted syntax?

14:56:20 <SteveH> AxelPolleres: apprently because the example after is suposed to be equivalent

14:56:28 <AxelPolleres> s/braketted/bracketed/

14:56:39 <Phil> Lee: Simpler examples on sub-select wiki might help.

14:56:39 <Phil> Orri: There have been simpler social-networking examples in the mailing lists.

14:56:43 <SteveH> sorry, AxelPolleres, not :

14:57:33 <john-l> I'm not familiar with TPC.

14:57:40 <chimezie> i am not familiar, unfortunately

14:57:40 <LukeWM> I'm not either

14:58:58 <Phil> Many folks are not familiar with the TPC queries; therefore, the simplest queries should be used for all of the feature categories (instead of the more complex TPC queries).

14:58:58 <LeeF> q?

14:59:06 <LeeF> ack chimezie

14:59:06 <Zakim> chimezie, you wanted to suggest we consider restricted subselects rather than all or nothing

14:59:33 <LeeF> ack SteveH

14:59:33 <Zakim> SteveH, you wanted to disagree with eric

15:00:04 <LeeF> SteveH: adding too many surface syntax features makes query language complicated

15:00:05 <Souri> I am somewhat familiar, but we should decouple the examples from TPC benchmark to explain the utility.

15:00:15 <LeeF> zakim, who's here?

15:00:15 <Zakim> On the phone I see LukeWM, AndyS, john-l (muted), kasei (muted), Lee_Feigenbaum, iv_an_ru, Ivan, AxelPolleres, AlexPassant, SteveH, EricP, kjetil (muted), Orri, Phil,

15:00:25 <Zakim> On IRC I see Souri, ywang4, chimezie, Phil, AlexPassant, kasei, SteveH, RRSAgent, Zakim, AndyS, AxelPolleres, john-l, LukeWM, ivan, AndyS_, iv_an_ru, LeeF, sandro, kjetil,

15:00:21 <Zakim> ... Chimezie_Ogbuji, DaveNewman, Souri, ywang4

15:00:21 <SteveH> +1

15:00:21 <AlexPassant> 0

15:00:23 <john-l> +0

15:00:25 <Phil> Polling for sub-selects:

15:00:28 <Zakim> ... trackbot, ericP

15:00:29 <kasei> +0

15:00:31 <LukeWM> +1

15:00:32 <iv_an_ru> +1

15:00:33 <kjetil> +1

15:00:33 <chimezie> +0

15:00:35 <ericP> SteveH, i understand your point. would like to look in detail with you

15:00:35 <ericP> -1

15:00:42 <Souri> +0.75

15:00:42 <ivanh> +0

15:00:42 <LeeF> Orri: 1

15:00:42 <Phil> +0

15:00:53 <LeeF> David: +1

15:01:00 <LeeF> +0

15:01:06 <AxelPolleres> +0

15:01:11 <AndyS> +1

15:01:23 <SteveH> ericP, yes, sure

15:01:47 <ericP> my hunch is that the verb count ends up the same

15:01:50 <chimezie> take care

15:01:56 <Phil> meeting adjourned.