SPARQL Working Group Teleconference

Minutes of 09 November 2010

Agenda

http://www.w3.org/2009/sparql/wiki/Agenda-2010-11-09

Present

Lee Feigenbaum, Souripriya Das, Paul Gearon, Gregory Williams, Carlos Buil Aranda, Andy Seaborne

Regrets

Axel Polleres, Alexandre Passant, Ivan Herman, Birte Glimm, Nicholas Humfrey, Olivier Corby, Steve Harris

Chair

Lee Feigenbaum

Scribe

Andy Seaborne

IRC Log

Original and Editable Wiki Version

Resolutions

1. Approve minutes at http://www.w3.org/2009/sparql/meeting/2010-11-02 link

Topics

1. Admin

2. update shortcuts

   slight preference in today's group for including shortcuts - motivation is ease of use of language, ease of optimization

3. grouping by expressions

4. Function library

5. test cases

14:57:05 <trackbot> Meeting: SPARQL Working Group Teleconference

14:57:05 <trackbot> Date: 09 November 2010

14:57:00 <RRSAgent> Present: LeeF, Souri, pgearon, kasei, cbuilara, AndyS

14:57:22 <LeeF> Agenda: http://www.w3.org/2009/sparql/wiki/Agenda-2010-11-09

14:57:24 <LeeF> Chair: LeeF

14:58:00 <LeeF> Regrets: Axel, Alex, Ivan, bglimm, NickH, Olivier, SteveH

15:04:23 <AndyS> scribenick: AndyS

(Scribe set to Andy Seaborne)

15:04:28 <AndyS> Scribe: Andy Seaborne

15:04:28 <cbuilara> I will add my self to the scribe list

Carlos Buil Aranda: I will add my self to the scribe list ←

15:04:38 <LeeF> topic: Admin

15:04:39 <LeeF> PROPOSED: Approve minutes at http://www.w3.org/2009/sparql/meeting/2010-11-02

PROPOSED: Approve minutes at http://www.w3.org/2009/sparql/meeting/2010-11-02 ←

15:05:57 <LeeF> RESOLVED: Approve minutes at http://www.w3.org/2009/sparql/meeting/2010-11-02

RESOLVED: Approve minutes at http://www.w3.org/2009/sparql/meeting/2010-11-02 ←

15:06:18 <LeeF> Next regular meeting: 2010-11-16 @ 15:00 UK / 10:00 EST (Scribe: Chime with NickH as backup)

Lee Feigenbaum: Next regular meeting: 2010-11-16 @ 15:00 UK / 10:00 EST (Scribe: Chime with NickH as backup) ←

15:06:34 <LeeF> Regrets next week: LeeF

Lee Feigenbaum: Regrets next week: LeeF ←

15:06:59 <AndyS> Partial meeting due to ISWC

Partial meeting due to ISWC ←

15:07:02 <LeeF> http://www.w3.org/2009/sparql/track/issues/16

Lee Feigenbaum: http://www.w3.org/2009/sparql/track/issues/16 ←

15:09:00 <kasei> q+

Gregory Williams: q+ ←

15:09:07 <LeeF> ack kasei

Lee Feigenbaum: ack kasei ←

15:09:51 <AndyS> Consensus emerging around text in doc : e.g. strict sum using op:numeric-add

Consensus emerging around text in doc : e.g. strict sum using op:numeric-add ←

15:10:20 <AndyS> q+

q+ ←

15:10:51 <AndyS> q-

q- ←

15:10:54 <LeeF> for next week: PROPOSED: Close ISSUE-16 by noting that aggregates define their semantics over mixed data types which can include errors, errors that propagate to a SELECT list result in an unbound variable, errors that propagate to GROUP BY clause result in an "unbound" key

Lee Feigenbaum: for next week: PROPOSED: Close ISSUE-16 by noting that aggregates define their semantics over mixed data types which can include errors, errors that propagate to a SELECT list result in an unbound variable, errors that propagate to GROUP BY clause result in an "unbound" key ←

15:11:09 <AndyS> http://www.w3.org/2009/sparql/docs/query-1.1/rq25.xml#setFunctions

http://www.w3.org/2009/sparql/docs/query-1.1/rq25.xml#setFunctions ←

15:12:04 <LeeF> AndyS: formal section will say that syntax -> algebra is 3 steps (instead of current 2)

Andy Seaborne: formal section will say that syntax -> algebra is 3 steps (instead of current 2) [ Scribe Assist by Lee Feigenbaum ] ←

15:12:08 <LeeF> ... graph patterns, grouping, solution modifiers

Lee Feigenbaum: ... graph patterns, grouping, solution modifiers ←

15:12:42 <LeeF> ... grouping works over multisets, solution modifiers work over sequences

Lee Feigenbaum: ... grouping works over multisets, solution modifiers work over sequences ←

15:16:04 <pgearon> +q

Paul Gearon: +q ←

15:16:22 <LeeF> ACTION: Lee to review the text that contributes to the proposed resolution of ISSUE-16

ACTION: Lee to review the text that contributes to the proposed resolution of ISSUE-16 ←

15:16:22 <trackbot> Created ACTION-332 - Review the text that contributes to the proposed resolution of ISSUE-16 [on Lee Feigenbaum - due 2010-11-16].

Trackbot IRC Bot: Created ACTION-332 - Review the text that contributes to the proposed resolution of ISSUE-16 [on Lee Feigenbaum - due 2010-11-16]. ←

15:16:24 <AndyS> ack pgearon

ack pgearon ←

15:16:27 <LeeF> ack pgearon

Lee Feigenbaum: ack pgearon ←

15:16:49 <AndyS> pgearon: Q about differing types for sum:

Paul Gearon: Q about differing types for sum: ←

15:17:53 <AndyS> LeeF: defn using op:numeric-add => error to add non-number.

Lee Feigenbaum: defn using op:numeric-add => error to add non-number. ←

15:18:22 <AndyS> ... when used in SELECT expressions erro=> unbound (extend operator)

... when used in SELECT expressions erro=> unbound (extend operator) ←

15:19:38 <pgearon> q-

Paul Gearon: q- ←

15:19:48 <LeeF> pgearon: not clear from text what happens when an error is encountered midway through a SUM evaluation

Paul Gearon: not clear from text what happens when an error is encountered midway through a SUM evaluation [ Scribe Assist by Lee Feigenbaum ] ←

15:20:17 <LeeF> topic: update shortcuts

15:20:18 <LeeF> http://www.w3.org/2009/sparql/docs/update-1.1/shortcuts.xml

Lee Feigenbaum: http://www.w3.org/2009/sparql/docs/update-1.1/shortcuts.xml ←

15:21:12 <AndyS> LeeF: concerns at shortcuts this early in life of SPARQL 1.1

Lee Feigenbaum: concerns at shortcuts this early in life of SPARQL 1.1 ←

15:22:14 <AndyS> ... Shortcuts: ADD, MOVE, COPY

... Shortcuts: ADD, MOVE, COPY ←

15:22:39 <kasei> I'm mildly opposed to the shortcuts. Same concerns as LeeF.

Gregory Williams: I'm mildly opposed to the shortcuts. Same concerns as LeeF. ←

15:22:44 <AndyS> ... analogs of the file operations and similar to REST operations.

... analogs of the file operations and similar to REST operations. ←

15:22:46 <Souri> ADD => is the semantics like a MERGE? b/c we may have duplicates

Souripriya Das: ADD => is the semantics like a MERGE? b/c we may have duplicates ←

15:22:56 <Souri> q+

Souripriya Das: q+ ←

15:23:01 <LeeF> ack Souri

Lee Feigenbaum: ack Souri ←

15:24:15 <AndyS> AndyS: Usage experience - quickly started using them after adding them for remote admin of datasets.

Andy Seaborne: Usage experience - quickly started using them after adding them for remote admin of datasets. ←

15:24:18 <AndyS> Strawpoll:

STRAWPOLL: ←

15:24:26 <LeeF> straw poll on proposed ADD/COPY/MOVE update shortcuts (+1/0/-1):

Lee Feigenbaum: straw poll on proposed ADD/COPY/MOVE update shortcuts (+1/0/-1): ←

15:24:31 <AndyS> +1

+1 ←

15:24:32 <LeeF> -1

Lee Feigenbaum: -1 ←

15:24:33 <kasei> -1

Gregory Williams: -1 ←

15:24:33 <Souri> +1

Souripriya Das: +1 ←

15:24:34 <pgearon> 0

Paul Gearon: 0 ←

15:25:25 <cbuilara> +1

Carlos Buil Aranda: +1 ←

15:26:24 <Souri> q+

Souripriya Das: q+ ←

15:26:40 <LeeF> LeeF: I am motivated a bit by hearing positive implementation and usage experience from AndyS

Lee Feigenbaum: I am motivated a bit by hearing positive implementation and usage experience from AndyS [ Scribe Assist by Lee Feigenbaum ] ←

15:26:43 <LeeF> ack Souri

Lee Feigenbaum: ack Souri ←

15:27:23 <LeeF> Souri: easier to spot optimizations for the shortcut operations

Souripriya Das: easier to spot optimizations for the shortcut operations [ Scribe Assist by Lee Feigenbaum ] ←

15:28:00 <LeeF> summary: slight preference in today's group for including shortcuts - motivation is ease of use of language, ease of optimization

15:28:17 <LeeF> topic: grouping by expressions

15:28:27 <AndyS> http://lists.w3.org/Archives/Public/public-rdf-dawg/2010OctDec/0187.html

15:28:45 <LeeF> (btw, the last conversation dealt with ISSUE-59)

15:29:22 <AndyS> (no issue for the issue of GROUP BY expression)

15:29:45 <AndyS> LeeF summary/proposal possibilities: 0187

15:30:23 <AndyS> ... WG wanted to do in principle - mechanism postponed last time.

15:31:00 <LeeF> option 1 - To project grouping expressions, use BIND to alias the expression to

15:31:00 <LeeF> a variable and then GROUP BY and project that variable (as above).

15:31:25 <LeeF> option 2 - Include an AS aliasing mechanism in GROUP BY, allow that alias to be

15:31:25 <LeeF> projected in the SELECT clause

15:32:34 <AndyS> Discussion around opt 2 and opt 1.

15:32:49 <LeeF> q?

15:32:59 <AndyS> SteveH noted wish for if opt 2, then allow no AS form as well.

15:33:00 <Souri> q+

15:33:07 <LeeF> ack Souri

15:33:48 <AndyS> Souri: Q about BIND and GROUP BY

15:33:55 <LeeF> SELECT ... ?x ... WHERE { .... BIND ( ?x AS expr ) } GROUP BY ?x

15:34:18 <kasei> that BIND is backwards, no?

15:34:25 <LeeF> SELECT ... ?x ... WHERE { .... } GROUP BY (expr AS ?x)

15:34:39 <LeeF> should have been BIND ( expr AS ?x )

15:35:51 <AndyS> SELECT .... WHERE { .... } GROUP BY (expr AS ?x)

15:36:00 <AndyS> SELECT .... WHERE { .... } GROUP BY (expr)

15:36:44 <LeeF> (general consensus against _requiring_ alias when grouping by expressions)

15:36:59 <LeeF> straw poll: allow option 2 (include AS aliasing in GROUP BY syntax) (+1/0/-1)

15:37:49 <LeeF> straw poll: allow option 2 (include expressions and AS aliasing in GROUP BY syntax) (+1/0/-1)

15:37:58 <kasei> +1

15:38:00 <LeeF> 0

15:38:04 <AndyS> +1

15:38:13 <Souri> +1

15:38:20 <cbuilara> 0

15:38:25 <pgearon> 0

15:39:43 <LeeF> for next week: PROPOSED: The GROUP BY clause can include expressions with or without AS aliases. These aliases can be re-used in the HAVING clause and query result clause

15:39:46 <pgearon> I don't see the need for it when a BIND in the WHERE clause will work just as well. But I don't have a particular problem with it, so I voted 0 instead of -1

15:39:48 <AndyS> leeF: is teh ?x usable in HAVING?

15:39:51 <AndyS> AndyS; yes

15:40:00 <Souri> q+

15:40:10 <AndyS> Topic: Function library

15:40:29 <LeeF> ack souri

15:42:10 <AndyS> group - extend - having

15:43:00 <AndyS> LeeF: will discuss in full group

15:43:06 <pgearon> +q

15:43:11 <LeeF> ack pgearon

15:45:39 <kasei> also, specifying an algorithm would prevent implementations from doing something better (like sourcing from random.org :)

15:45:41 <pgearon> -q

15:46:25 <pgearon> I'd prefer not to see a specified algorithm, but I wanted to raise it because it results in an untestable feature

15:46:41 <AndyS> Topic: test cases

15:46:44 <kasei> I believe I'm passing all the non-entailment tests right now

15:47:00 <AndyS> LeeF: need to keep building test case materials

15:47:09 <AndyS> ... but currently on track

15:47:41 <AndyS> ADJOURNED

15:53:29 <Zakim> SW_(SPARQL)10:00AM has ended

15:53:31 <Zakim> Attendees were LeeF, Souri, pgearon, kasei, cbuilara, AndyS