IRC log of sparql on 2009-05-19

Timestamps are in UTC.

13:55:44 [RRSAgent]

RRSAgent has joined #sparql

13:55:44 [RRSAgent]

logging to http://www.w3.org/2009/05/19-sparql-irc

13:56:04 [SimonS]

SimonS has joined #sparql

13:56:11 [Zakim]

Zakim has joined #sparql

13:56:19 [AxelPolleres]

Zakim, this is SPARQL

13:56:19 [Zakim]

AxelPolleres, I see SW_(SPARQL)10:00AM in the schedule but not yet started. Perhaps you mean "this will be SPARQL".

13:56:26 [AxelPolleres]

Zakim, this will be SPARQL

13:56:26 [Zakim]

ok, AxelPolleres; I see SW_(SPARQL)10:00AM scheduled to start in 4 minutes

13:57:00 [pgearon]

pgearon has joined #sparql

13:57:04 [LeeF]

trackbot, start meeting

13:57:06 [trackbot]

RRSAgent, make logs world

13:57:08 [trackbot]

Zakim, this will be 77277

13:57:08 [Zakim]

ok, trackbot; I see SW_(SPARQL)10:00AM scheduled to start in 3 minutes

13:57:09 [trackbot]

Meeting: SPARQL Working Group Teleconference

13:57:09 [trackbot]

Date: 19 May 2009

13:57:44 [Zakim]

SW_(SPARQL)10:00AM has now started

13:57:46 [LukeWM]

LukeWM has joined #sparql

13:57:51 [Zakim]

+ +1.216.445.aaaa

13:58:00 [john-l]

Zakim, aaaa is me

13:58:00 [Zakim]

+john-l; got it

13:58:22 [Zakim]

+ +3539149aabb

13:58:25 [Zakim]

-john-l

13:58:26 [Zakim]

+john-l

13:58:34 [Zakim]

+??P20

13:58:37 [AndyS]

zakim, ??P20 is me

13:58:37 [Zakim]

+AndyS; got it

13:58:40 [Zakim]

+[IPcaller]

13:58:54 [Zakim]

+ +0005aacc

13:58:56 [Zakim]

+ +1.312.863.aadd

13:58:57 [Zakim]

+??P18

13:59:08 [KjetilK]

Zakim: ??P18 is me

13:59:09 [AxelPolleres]

Zakim, who is speaking?

13:59:14 [KjetilK]

Zakim, ??P18 is me

13:59:14 [Zakim]

+KjetilK; got it

13:59:14 [kasei]

Zakim, IPcaller is me

13:59:15 [Zakim]

+kasei; got it

13:59:20 [Zakim]

+??P26

13:59:21 [Zakim]

AxelPolleres, listening for 10 seconds I could not identify any sounds

13:59:25 [KjetilK]

Zakim, mute me

13:59:25 [Zakim]

KjetilK should now be muted

13:59:26 [bijan]

zakim, ??p26 is me

13:59:26 [Zakim]

+bijan; got it

13:59:28 [SimonS]

Zakim, aacc is me

13:59:29 [Zakim]

+SimonS; got it

13:59:37 [SteveH]

SteveH has joined #sparql

13:59:38 [AxelPolleres]

Zakim, who is on the phone?

13:59:41 [Zakim]

On the phone I see john-l, AxelPolleres, AndyS, kasei, +1.312.863.aadd, SimonS, KjetilK (muted), bijan

14:00:04 [AxelPolleres]

Zakim, mute me

14:00:04 [Zakim]

AxelPolleres should now be muted

14:00:11 [kasei]

Zakim, mute me

14:00:22 [Zakim]

kasei should now be muted

14:00:29 [AxelPolleres]

Zakim, mute aadd

14:00:44 [Zakim]

+1.312.863.aadd should now be muted

14:00:55 [Zakim]

+??P28

14:01:13 [SteveH]

P28 might be me, not sure

14:01:16 [Zakim]

+??P29

14:01:17 [Zakim]

+Lee_Feigenbaum

14:01:18 [SteveH]

there was a big delay

14:01:29 [LeeF]

zakim, who's on the phone?

14:01:29 [Zakim]

On the phone I see john-l, AxelPolleres (muted), AndyS, kasei (muted), +1.312.863.aadd (muted), SimonS, KjetilK (muted), bijan, ??P28, ??P29, Lee_Feigenbaum

14:01:30 [AlexPassant]

Zakim: ??P28 is me

14:01:34 [AlexPassant]

Zakim, ??P28 is me

14:01:34 [Zakim]

+AlexPassant; got it

14:01:44 [SteveH]

I'll dial out and back so I get the number...

14:01:49 [Zakim]

-AlexPassant

14:01:59 [AlexPassant]

oh, so I'm not P28 :)

14:02:14 [AlexPassant]

Zakim, ??P29 is me

14:02:14 [Zakim]

+AlexPassant; got it

14:02:22 [Zakim]

+??P28

14:02:31 [SteveH]

Zakim, ??P28 is [Garlik]

14:02:31 [Zakim]

+[Garlik]; got it

14:02:40 [SteveH]

Zakim, [Garlik] has SteveH, LukeWM

14:02:40 [Zakim]

+SteveH, LukeWM; got it

14:02:55 [LeeF]

zakim, unmute aadd

14:02:56 [Zakim]

+1.312.863.aadd should no longer be muted

14:03:14 [AxelPolleres]

Zakim, unmute me

14:03:14 [Zakim]

AxelPolleres should no longer be muted

14:03:32 [bijan]

looking it up

14:03:45 [Zakim]

+ +1.937.775.aaee

14:03:55 [AxelPolleres]

up: #41. hand down: #40

14:03:55 [bijan]

41#

14:04:08 [bijan]

http://www.w3.org/2002/01/UsingZakim

14:04:24 [LeeF]

zakim, aadd is pgearon

14:04:24 [Zakim]

+pgearon; got it

14:04:26 [LeeF]

q-

14:04:32 [Zakim]

+EricP

14:04:50 [LeeF]

zakim, 937 is prateek

14:04:50 [Zakim]

sorry, LeeF, I do not recognize a party named '937'

14:04:58 [LeeF]

zakim, aaee is prateek

14:04:58 [Zakim]

+prateek; got it

14:05:02 [LeeF]

zakim, who's on the phone?

14:05:02 [Zakim]

On the phone I see john-l, AxelPolleres, AndyS, kasei (muted), pgearon, SimonS, KjetilK (muted), bijan, AlexPassant, Lee_Feigenbaum, [Garlik], prateek, EricP

14:05:06 [Zakim]

[Garlik] has SteveH, LukeWM

14:05:39 [Prateek]

Prateek has joined #sparql

14:05:47 [bijan]

scribenick: bijan

14:06:35 [LeeF]

topic: admin

14:06:42 [LeeF]

PROPOSED: Approve minutes at http://www.w3.org/2009/sparql/meeting/2009-04-28

14:07:03 [AxelPolleres]

+1

14:07:13 [LeeF]

RESOLVED: Approve minutes at http://www.w3.org/2009/sparql/meeting/2009-04-28

14:07:13 [bijan]

bijan has changed the topic to: http://www.w3.org/2009/sparql/wiki/Agenda-2009-05-19

14:07:37 [bijan]

AndyS: Pity that the new minutes don't group axioms

14:07:44 [bijan]

LeeF: Pester Sanrdo.

14:07:56 [bijan]

s/axioms/actions/

14:08:18 [bijan]

LeeF: Meeting next week, same bat time, same bat channel, chime as scribe

14:08:25 [bijan]

Topic: Liasons

14:08:34 [bijan]

LeeF: Anything we need to know?

14:08:36 [bijan]

Crickets.

14:08:48 [AxelPolleres]

q+ on rdf-text

14:08:51 [bijan]

ericP: Lots of hot rdf:text action

14:08:51 [AlexPassant]

q+ to ask about Social Web XG liaison

14:08:54 [LeeF]

q- aadd

14:09:02 [LeeF]

q- +1.312.863.aadd

14:09:42 [bijan]

...What I can gather is that people are ok with inferred rdf:text being invisible to sparql query. But AndyS gave 3 proposals and I was in favor of 1. AndyS could you list them?

14:09:43 [LeeF]

q-i AxelPolleres

14:09:52 [bijan]

AndyS: Now? Is it agenda sane?

14:10:13 [bijan]

AxelPolleres: We are due to set up a telecon with all the related parties on it. Soon.

14:10:34 [bijan]

LeeF: Let's defer to the looped people until we have a proposed resolution.

14:10:46 [bijan]

...Any non-looped callers want to talk about it?

14:10:50 [bijan]

<crickets>

14:10:55 [SteveH]

not sure if I'm in the loop or not... I was

14:10:59 [LeeF]

ack AlexPassant

14:10:59 [Zakim]

AlexPassant, you wanted to ask about Social Web XG liaison

14:11:21 [bijan]

AlexPassant: There's a new XG on Social Web and I'd like to be the liaison for that

14:11:28 [bijan]

LeeF: Superfantastic!

14:11:30 [AndyS]

-> http://lists.w3.org/Archives/Public/public-rdf-text/2009AprJun/0083.html

14:11:45 [bijan]

Topic: F2F1 recap

14:11:52 [AlexPassant]

http://www.w3.org/2005/Incubator/socialweb/

14:11:52 [LeeF]

-> http://www.w3.org/2009/sparql/meeting/2009-05-06

14:11:56 [LeeF]

-> http://www.w3.org/2009/sparql/meeting/2009-05-07

14:12:18 [LeeF]

-> http://www.w3.org/2009/sparql/wiki/FeatureProposal

14:12:20 [bijan]

LeeF: The minutes are about ready, see links.

14:13:09 [bijan]

...we've decided to work on some things and we decided on a naming scheme, i.e., SPARQL/*, e.g., SPARQL/Query SPARQL/Update

14:13:38 [bijan]

...Sublanguages are independently versions, thus DAWG SPARQL/Query is 1.0 and our SPARQL/Query is 1.1

14:13:50 [bijan]

...Something about subselect or something

14:14:20 [bijan]

...Following AndyS's suggestion we'll have a wiki design template for all sorts of spec development.

14:14:22 [bijan]

...Questions?

14:14:37 [AxelPolleres]

http://www.w3.org/2009/sparql/wiki/Template:DesignQL

14:15:01 [AxelPolleres]

Example:

14:15:02 [AxelPolleres]

http://www.w3.org/2009/sparql/wiki/Design:SubSelect

14:15:09 [bijan]

LeeF: Let's go over status of Actions both to close ones that are read and to shame people who are slackin'

14:15:34 [iv_an_ru]

:( I'm late with sub-SELECT samples :(

14:15:59 [bijan]

...Right now the tracker is set up so anyone can close actions (not axioms). But the chairs would prefer that people would not *close* actions when done but set them to "pending review" so the chairs have an easier time with bookkeeping.

14:16:13 [LeeF]

http://www.w3.org/2009/sparql/track/actions/open

14:16:19 [LeeF]

http://www.w3.org/2009/sparql/track/actions/pendingreview

14:17:08 [SteveH]

q+ to say about action UI

14:17:14 [bijan]

LeeF: Also, Bijan explained that tracker will track email about an action or issue if you include anywhere in an email (ISSUE|ACTION):d+ where :d+ is the relevant action/issue number

14:17:23 [bijan]

...so please do this!

14:17:24 [LeeF]

ack SteveH

14:17:24 [Zakim]

SteveH, you wanted to say about action UI

14:17:43 [SteveH]

http://www.w3.org/2009/sparql/track/actions/13

14:17:47 [bijan]

SteveH: It also picks up uris of the action/issue

14:18:07 [bijan]

LeeF: Cool.

14:18:12 [bijan]

q+ to pimp it

14:18:20 [LeeF]

ack bijan

14:18:20 [Zakim]

bijan, you wanted to pimp it

14:18:31 [LeeF]

bijan: OWL experience is that this is super duper useful

14:18:42 [Zakim]

-EricP

14:19:01 [bijan]

Topic: Pending review actions

14:19:26 [Zakim]

+EricP

14:19:36 [bijan]

LeeF: ACTION-14 (bijan). It's done.

14:19:43 [LeeF]

trackbot, close ACTION-14

14:19:43 [trackbot]

ACTION-14 Send mail about issues in specifying OWL in SPARQL semantics closed

14:20:26 [bijan]

LeeF: ACTION-18 (Axel). We'll talk about this later in the call. It's good.

14:20:39 [LeeF]

trackbot, close ACTION-18

14:20:39 [trackbot]

ACTION-18 Write up a use case on !ASK in FILTERS to emulate negation closed

14:21:13 [LeeF]

trackbot, close ACTION-20

14:21:13 [trackbot]

ACTION-20 Send CONSTRUCT in FROM clause use case to mailing list re: ISSUE-7 closed

14:21:43 [LeeF]

trackbot, close ACTION-24

14:21:43 [trackbot]

ACTION-24 Explain potential design regarding aggregate functions with multiple answers for mixed datatypes re ISSUE-16 closed

14:22:22 [LeeF]

trackbot, close ACTION-25

14:22:22 [trackbot]

ACTION-25 Setup wiki template and feature stub pages based on slide 11 of http://jena.hpl.hp.com/~afs/SPARQL-F2F1-AFS.pdf closed

14:22:24 [LeeF]

trackbot, close ACTION-26

14:22:24 [trackbot]

ACTION-26 Stub out an initial example of a filled in feature template pending completion of ACTION-25 closed

14:23:02 [LeeF]

trackbot, close ACTION-27

14:23:02 [trackbot]

ACTION-27 Ask in DERI about whether RDF Forms/pushback uses WHERE in updates closed

14:23:21 [LeeF]

trackbot, close ACTION-30

14:23:21 [trackbot]

ACTION-30 Provide 3 uses cases on wiki closed

14:23:53 [LeeF]

trackbot, close ACTION-13

14:23:53 [trackbot]

ACTION-13 Write up how/whether assignment is subsumed by projected expressions + subqueries (tentative, with LukeWM) closed

14:24:13 [LeeF]

trackbot, close ACTION-29

14:24:13 [trackbot]

ACTION-29 Provide FOAF update use case on wiki closed

14:25:29 [bijan]

Topic: Review Template:DesignQL

14:25:32 [bijan]

http://www.w3.org/2009/sparql/wiki/Template:DesignQL

14:26:16 [bijan]

LeeF: We can use this to put competing designs and even language side by side. AndyS?

14:27:13 [bijan]

AndyS: This is a bit tuned for the query language. Design early and often for concrete direction. <<Gives a blow by blow over template>>

14:28:03 [AndyS]

"design early - design often"

14:28:33 [bijan]

LeeF: And people should feel free to add bits to arbitrary sections.

14:28:54 [LeeF]

-> http://www.w3.org/2009/sparql/wiki/Design:SubSelect

14:29:11 [bijan]

LeeF: Check out AndyS's first example for SubSelect

14:29:46 [bijan]

Topic: F&R document update?

14:30:04 [AlexPassant]

http://www.w3.org/2009/sparql/docs/features/

14:30:30 [bijan]

LeeF: Who's the audience? Potential implementors? WG wannabees? Users? AC reps?

14:30:50 [bijan]

...My answer is that this should target implementors and WG wannabees.

14:31:25 [AndyS]

+1 to keeping syntax up-to-date -- it caused people some confusion last time when we left old syntax around.

14:31:34 [bijan]

...I think we should maintain the syntax in the document because these documents are like diamonds...forever. So we can avoid people who stumble on the F&R won't be confused.

14:31:35 [iv_an_ru]

+1

14:31:48 [SteveH]

I suspect the F&R should avoid syntax whereever possible

14:31:59 [bijan]

...However, I don't intend the N&F isn't a primer. So, concise, technical document.

14:32:05 [AlexPassant]

+1 for updating syntax when the WG agrees on it

14:32:12 [KjetilK]

Zakim, unmute me

14:32:15 [SteveH]

q+

14:32:16 [Zakim]

KjetilK should no longer be muted

14:32:51 [bijan]

kjetil: My primary concern is how it'll be seen by people outside the SPARQL community. Current stuff is a bit terse.

14:33:19 [bijan]

LeeF: I sorta agree. I don't know what sort of review to expect. I think it's ok to presume familiarity with SPARQL

14:33:22 [bijan]

q+

14:33:26 [LeeF]

ack SteveH

14:34:00 [bijan]

SteveH: I think we should avoid putting in speculative syntax whenever possible. Showing what can't be done is ok, but people *will* implement any scrap of anything no matter what the disclaimers.

14:34:13 [bijan]

LeeF: What about linking out to existing implementations.

14:34:27 [bijan]

SteveH: That should be ok. But w3.org makes people crazy.

14:34:31 [LeeF]

ack bijan

14:34:38 [KjetilK]

q+

14:34:56 [LeeF]

bijan: recommend narrow scope, don't worry about general audience (which would cause a lot of extra work)

14:35:02 [SteveH]

+1 to not worrying about general audience, meant to say that too

14:35:11 [LeeF]

ack KjetilK

14:35:27 [bijan]

KJetikK: I'm worried that people will come and say it's not well motivated.

14:35:31 [bijan]

I don't think it's a worry.

14:35:59 [bijan]

LeeF: I'm not too worried about it. I expect most feedback from the implementors community.

14:36:19 [bijan]

Also, if someone does have a question, we can deal with it as it arises.

14:36:30 [KjetilK]

Zakim, mute me

14:36:30 [Zakim]

KjetilK should now be muted

14:36:37 [bijan]

Topic: Feature overview: Feature:Negation

14:36:49 [bijan]

http://www.w3.org/2009/sparql/wiki/Feature:Negation

14:36:49 [LeeF]

-> http://www.w3.org/2009/sparql/wiki/Feature:Negation

14:37:26 [bijan]

LeeF: So, let's follow the F2F pattern. First get a sense of existing implementions. Fine design issues and start workign on it.

14:37:59 [bijan]

...Start with overview. Take it to email. Move things back to telecon on a "obvious need" basis.

14:38:54 [bijan]

...Kicking off negation discussion. You can do just about all the use cases in S/Q 1.0 using optional and notbound. Which is so ugly I'd rather watch videos of parasitic wasps emerging from their catapiller hosts.

14:39:18 [bijan]

...There are several design out there, but I'd like to know what people do now.

14:39:35 [LeeF]

zakim, who's here?

14:39:35 [Zakim]

On the phone I see john-l, AxelPolleres, AndyS, kasei (muted), pgearon, SimonS, KjetilK (muted), bijan, AlexPassant, Lee_Feigenbaum, [Garlik], prateek, EricP

14:39:37 [bijan]

...AndyS, do you have an implementation of simpler negation?

14:39:39 [Zakim]

[Garlik] has SteveH, LukeWM

14:39:40 [Zakim]

On IRC I see Prateek, SteveH, LukeWM, pgearon, Zakim, SimonS, RRSAgent, AxelPolleres, john-l, bijan, AndyS, karl, AndyS_, LeeF, trackbot, iv_an_ru, kasei, kjetil, AlexPassant,

14:39:43 [Zakim]

... KjetilK, ericP

14:39:48 [kasei]

Zakim, unmute me

14:39:48 [Zakim]

kasei should no longer be muted

14:39:53 [bijan]

AndyS: Nothing in release version. Most of my thoughts go back to UNSAID in DAWG.

14:40:07 [ericP]

i implemented UNSAID in Algae2

14:40:09 [ericP]

it worked

14:40:12 [ericP]

.

14:40:38 [bijan]

kasei: We do UNSAID.

14:40:52 [bijan]

pgearon: we have a minus operator.

14:40:53 [AlexPassant]

no negation in ARC2/SPARQL+

14:40:58 [bijan]

LeeF: Is that like UNSAID?

14:41:06 [bijan]

pgearon: sorta

14:41:12 [AndyS]

q+ to ask about MINUS

14:41:26 [AxelPolleres]

Sesame/SeRQL has MINUS

14:41:40 [LeeF]

ack AndyS

14:41:40 [Zakim]

AndyS, you wanted to ask about MINUS

14:41:41 [AxelPolleres]

SimonS: Sesame/SeRQL has MINUS

14:42:03 [bijan]

AndyS: Is your minus a set based (each side has to have the same shape) or not?

14:42:22 [bijan]

pgearon: It's set based. It's sorta like an inner join. I have a posting that describes that it detail.

14:42:30 [bijan]

AndyS: Please send the pointer?

14:42:37 [bijan]

pgearon: I'm looking for it.

14:42:59 [bijan]

bijan: None of the owl ones do, to my knowledge.

14:43:08 [SimonS]

q+ to summarize MINUS in SeRQL

14:43:16 [bijan]

LeeF: because I'm a sadist, glitter forces you to do it the waspy way

14:43:22 [bijan]

SteveH: We don't do it.

14:43:46 [bijan]

Prateek: We don't have it.

14:43:56 [LeeF]

iv_an_ru, what does Virtuoso do for negation?

14:43:59 [bijan]

LeeF: Anyone know what Virtuoso?

14:44:05 [bijan]

AndyS: The might have exists?

14:44:09 [pgearon]

I wrote about my description of MINUS in a blog post 2004-10-05: http://gearon.blogspot.com/2004/10/owlsameas-majority-of-today-was-spent.html

14:44:11 [AxelPolleres]

we had some very prototypical implementation of ASK in FILTERs ind dlvhex (LP engine based SPARQL implementation)... not released.

14:44:20 [pgearon]

(skip the first section on owl:sameAs)

14:44:21 [iv_an_ru]

we have subqueries and ! operator, that's enough

14:44:28 [SimonS]

http://www.openrdf.org/doc/sesame2/users/ch09.html#d0e2194

14:44:37 [iv_an_ru]

We don't have MINUS or UNSAID

14:44:50 [bijan]

SimonS: I checked the docs and found that minus is set based in Seqrl and exists which is Not...something

14:44:54 [iv_an_ru]

We've never seen requests for them

14:45:18 [bijan]

SimonS: Minus is an operator that takes two queries and from the results of the first query remove the elements of the second query.

14:45:31 [LeeF]

s/...something/ ASK/

14:45:41 [bijan]

...EXISTS is NOT ASK filter

14:46:00 [pgearon]

sounds like the two sets must bind the same variables, is that right?

14:46:12 [bijan]

LeeF: I presume a good deal of discussion will revolve around which sort, but we're going to defer.

14:46:24 [bijan]

...From what we've just heard and discussion on the list there are three designs:

14:46:40 [bijan]

...1) Binary operator that acts on subqueries (SERQL Minus)

14:46:55 [bijan]

...2) Binary operator *in* a graph pattern (e.g., UNSAID)

14:47:40 [bijan]

...3) Not exists approach (filter based). AndyS pointed out in email that it wouldn't be exactly the semantics of the compositional form. So maybe a different name

14:47:58 [bijan]

LeeF: Does that design space seem right?

14:48:08 [bijan]

pgearon thinks the FILTER based approach is similar to a SQL left-outer-join

14:48:23 [bijan]

LeeF: Silence is UNSAID assent

14:48:34 [SteveH]

I don't understand pgearon's point

14:48:57 [bijan]

...We need to decide between these.

14:49:07 [AndyS]

FILTER/EXISTS is very like SQL EXISTS.

14:49:34 [iv_an_ru]

AndyS, the similarity is advantage ;)

14:49:37 [LeeF]

ISSUE: Should negation be done via a binary operator on subqueries, a binary operator within graph patterns, or a filter+subquery?

14:49:37 [trackbot]

Created ISSUE-29 - Should negation be done via a binary operator on subqueries, a binary operator within graph patterns, or a filter+subquery? ; please complete additional details at http://www.w3.org/2009/sparql/track/issues/29/edit .

14:50:18 [bijan]

LeeF: Get we get some voluteers for UNSAID and MINUS to talk designs on the mailing list.

14:50:19 [bijan]

q+

14:50:23 [bijan]

ericP: Plus contrasts

14:50:29 [LeeF]

q- SimonS

14:50:31 [SimonS]

q-

14:50:35 [bijan]

q-

14:50:42 [bijan]

bijan: Email or design template

14:50:46 [AxelPolleres]

ISSUE-29 relates to ISSUE-5 (how again do I bring trackbot to link that?)

14:50:50 [bijan]

AndyS: at first, email is better.

14:52:06 [Zakim]

-kasei

14:52:11 [bijan]

LeeF: I want to make the barrier to entry very low. So if they can put it in the template, great.

14:52:19 [bijan]

AndyS: Email is nice because it's push.

14:52:40 [bijan]

ericP: I'd love to work on UNSAID with SimonS since he has both

14:52:45 [LeeF]

ACTION: ericP to work with SimonS on explaining and comparing UNSAID and MINUS

14:52:45 [trackbot]

Sorry, couldn't find user - ericP

14:52:52 [LeeF]

ACTION: Eric to work with SimonS on explaining and comparing UNSAID and MINUS

14:52:52 [trackbot]

Created ACTION-32 - Work with SimonS on explaining and comparing UNSAID and MINUS [on Eric Prud'hommeaux - due 2009-05-26].

14:53:15 [Zakim]

+??P5

14:53:23 [kasei]

Zakim, P5 is me

14:53:23 [Zakim]

sorry, kasei, I do not recognize a party named 'P5'

14:53:25 [bijan]

LeeF: pgearon and kasei if you want to chime in, please do in email

14:53:55 [KjetilK]

Zakim, ??P5 is kasei

14:53:55 [Zakim]

+kasei; got it

14:54:06 [kasei]

thanks KjetilK

14:54:18 [bijan]

LeeF: Any other questions or discussions about negation? iv_an_ru said on irc that they've received no request for negation in graph patterns. So contrasting experience?

14:54:31 [bijan]

ericP: When I did it I didn't have subselects, so it was the only obvious way to do it.

14:54:39 [bijan]

LeeF: Do you have a gut feeling now as to preference?

14:55:01 [SteveH]

+1 to ericP

14:55:05 [SteveH]

my feeling too

14:55:06 [bijan]

ericP: SQL users are used to a subselect and a not. But to me it has a similar feel to an optional so prefer the ingraph thing

14:55:12 [SimonS]

+1 to ericP

14:55:17 [bijan]

LeeF: kasei?

14:55:40 [bijan]

kasei: well, i don't have a lot of experience. I threw it it for kicks. I agree with ericP about the design.

14:56:12 [bijan]

LeeF: AndyS? When you had it what did you have?

14:56:16 [AxelPolleres]

q+

14:56:24 [KjetilK]

q+ to ask about optimisations

14:56:33 [bijan]

AndyS: It was UNSAID.

14:56:39 [iv_an_ru]

I have no technical difficulties with MINUS, we have a similar thing in SQL, but I don't know whether it will be popular.

14:56:48 [LeeF]

ack AxelPolleres

14:57:06 [bijan]

AxelPolleres: Does anyone have a preference *against* having both?

14:57:40 [bijan]

LeeF: From scuttlebut, there are people who prefer minimality. For me, I'd only have both if there was a clear functional difference.

14:57:55 [bijan]

AxelPolleres: Reversing it, is there use cases not covered by one but by the other

14:57:57 [AndyS]

I don't understand the usability of MINUS. We might be only a little bit better than OPTIONAL/!BOUND, but I hope Simon+Eric will show that to be a false worry.

14:58:02 [bijan]

ericP: [[scribe lost it]]

14:58:06 [iv_an_ru]

I'm lazy, that's the only reason I have agains MINUS

14:58:45 [LeeF]

ack kjetil

14:58:45 [pgearon]

AndyS, can you please elaborate?

14:58:47 [Zakim]

KjetilK, you wanted to ask about optimisations

14:58:55 [AxelPolleres]

UNSAID { } vs. FILTER ( !EXISTS { } ... any of the two more expressive?

14:59:02 [bijan]

ericP: My suspicious that given that object of an UNSAID is a graph pattern you could stick a subselect there which is a scribe tormenting way to say "No".

14:59:12 [bijan]

KjetilK: Does it matter for optimization?

14:59:29 [AxelPolleres]

UNSAID { } vs. FILTER ( !EXISTS { } ... any of the two easieer to optimize?

14:59:34 [bijan]

ericP: My guess is that UNSAID is easier to optimize because you can exhaust possibilities more easily

15:00:35 [AxelPolleres]

what if the EXISTS is wrapped into a more complext FILTER expression? Is that the same as wrapping the complex filter inside the UNSAID pattern?

15:00:49 [bijan]

AndyS: I think any of the cases can be done with either. FILTER(!EXISTS... makes it easier to combine with other conditions. UNSAID controls the position of the negation. Optimization: it should be easy to spot when FILTER(!exists is the same as an UNSAID

15:01:04 [SimonS]

AxelPolleres: Outside of the UNSAID.

15:01:14 [KjetilK]

Zakim, mute me

15:01:14 [Zakim]

KjetilK should now be muted

15:01:27 [Zakim]

-AxelPolleres

15:01:33 [AndyS]

{P} FILTER(!EXISTS{Q}) looks to me exactly the binary {P} UNSAID {Q} (he said boldly)

15:01:33 [LeeF]

q?

15:01:45 [bijan]

LeeF: Doesn't seem like a huge design space so we should be able to check each out and make progess.

15:01:53 [AndyS]

i.e. add {} to the lefty of filter form to foce order.

15:01:55 [SteveH]

AndyS, how sure of that are you?

15:02:15 [AndyS]

Very .. er .. reasonably

15:02:17 [bijan]

LeeF: Adjourned!

15:02:19 [SteveH]

ah, yeah, with the extra {}s

15:02:25 [Zakim]

-john-l

15:02:25 [Zakim]

-bijan

15:02:28 [AndyS]

Let's use the phone in a memo

15:02:29 [SteveH]

that's a bit of a special case though

15:02:34 [AndyS]

Let's use the phone in a mement.

15:03:28 [AndyS]

Yes - adding the {} controls the filter placement. It's a trick/idiom.

15:03:46 [Zakim]

-EricP

15:04:02 [KjetilK]

Zakim, who is on the phone?

15:04:02 [Zakim]

On the phone I see AndyS, pgearon, SimonS, KjetilK (muted), AlexPassant, Lee_Feigenbaum, [Garlik], prateek, kasei

15:04:04 [Zakim]

[Garlik] has SteveH, LukeWM

15:04:46 [Zakim]

-prateek

15:05:36 [KjetilK]

Zakim, unmute me

15:05:36 [Zakim]

KjetilK should no longer be muted

15:06:57 [Zakim]

-AlexPassant

15:07:14 [Zakim]

-SimonS

15:07:20 [SimonS]

SimonS has left #sparql

15:07:34 [pgearon]

most of the time I only need to "MINUS" a simple triple pattern, but the original use case needed a complex expression

15:08:07 [LeeF]

what was the original use case? is it written down somewhere?

15:08:22 [pgearon]

It was 5 years ago. :-)

15:08:57 [LeeF]

what's the statute of limitations on use cases? :)

15:09:38 [Zakim]

-kasei

15:10:00 [pgearon]

It was along the lines of: select everyone who :worksFor a department, exception those people who have rdf:type :Student and who have not submitted their thesis (indicated by {?student :wrote ?thesis . ?thesis :docType :Thesis . ?thesis dc:published ?publishDate {)

15:10:01 [Zakim]

-AndyS

15:10:03 [Zakim]

-KjetilK

15:10:16 [LukeWM]

LukeWM has joined #sparql

15:10:24 [Zakim]

-Lee_Feigenbaum

15:10:29 [Zakim]

-[Garlik]

15:10:31 [Zakim]

-pgearon

15:10:31 [Zakim]

SW_(SPARQL)10:00AM has ended

15:10:32 [Zakim]

Attendees were +1.216.445.aaaa, john-l, +3539149aabb, AndyS, AxelPolleres, +0005aacc, +1.312.863.aadd, KjetilK, kasei, bijan, SimonS, Lee_Feigenbaum, AlexPassant, SteveH, LukeWM,

15:10:34 [Zakim]

... +1.937.775.aaee, pgearon, EricP, prateek

15:10:59 [pgearon]

Essentially, the use case came down to whenever a query selected something "Except" a particular set of things

15:11:21 [pgearon]

The "except" was always an indicator

15:16:41 [AndyS]

I wonder if a style difference is between negation over individuals (more MINUS centric?) and over triples?

15:17:19 [pgearon]

That may be

15:17:21 [AndyS]

Or another way for individuals is !EXISTS(SELECT ?X{...})

15:18:51 [pgearon]

negation over triples seems to concentrate on simple BGPs, while negation over individuals makes it more natural to remove a GroupGraphPattern

15:19:07 [SteveH]

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15:19:46 [pgearon]

For individuals, yes, but it makes it hard if you need to remove things based on a tuple

15:20:16 [pgearon]

though I've only ever run into the need for that once, and it was years ago

15:45:32 [AxelPolleres]

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17:31:45 [Zakim]

Zakim has left #sparql

17:38:54 [SteveH]

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