IRC log of sparql on 2011-03-01

Timestamps are in UTC.

14:53:30 [RRSAgent]
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14:53:30 [RRSAgent]
logging to
14:53:36 [Zakim]
Zakim has joined #sparql
14:53:52 [AxelPolleres]
Zakim, this will be sparql
14:53:52 [Zakim]
ok, AxelPolleres; I see SW_(SPARQL)10:00AM scheduled to start in 7 minutes
14:56:14 [Zakim]
SW_(SPARQL)10:00AM has now started
14:56:21 [Zakim]
14:56:38 [SteveH]
Zakim, ??P11 is me
14:56:38 [Zakim]
+SteveH; got it
14:56:56 [Zakim]
14:57:03 [AndyS]
zakim, IPCaller is me.
14:57:03 [Zakim]
+AndyS; got it
14:57:25 [Zakim]
14:57:32 [Zakim]
14:57:38 [SteveH]
AndyS, did you just say something?
14:57:39 [NickH]
zakim, ??P13 is me
14:57:39 [Zakim]
+NickH; got it
14:58:06 [AndyS]
Yes - did you hear anytghing? I can't hear you. skype testing service worked though.
14:58:21 [SteveH]
I'm muted, one sec
14:58:43 [Zakim]
14:58:45 [cbuilara]
cbuilara has joined #sparql
14:58:48 [Zakim]
14:58:58 [NickH]
getting some echo
15:00:32 [MattPerry]
MattPerry has joined #sparql
15:00:48 [Zakim]
15:00:49 [AxelPolleres]
trackbot, start meeting
15:00:51 [trackbot]
RRSAgent, make logs world
15:00:53 [trackbot]
Zakim, this will be 77277
15:00:53 [Zakim]
ok, trackbot; I see SW_(SPARQL)10:00AM scheduled to start now
15:00:54 [trackbot]
Meeting: SPARQL Working Group Teleconference
15:00:54 [trackbot]
Date: 01 March 2011
15:01:06 [cbuilara]
zakim, IPcaller is me
15:01:06 [Zakim]
sorry, cbuilara, I do not recognize a party named 'IPcaller'
15:01:29 [AxelPolleres]
Zakim, who is on the phone?
15:01:29 [Zakim]
I notice SW_(SPARQL)10:00AM has restarted
15:01:30 [Zakim]
On the phone I see SteveH, AndyS, NickH, corby, kasei, pgearon, [IPcaller], AxelPolleres, Sandro, MattPerry
15:01:35 [cbuilara]
Zakim, IPcaller is me
15:01:35 [Zakim]
+cbuilara; got it
15:01:44 [cbuilara]
zakim, mute me
15:01:46 [Zakim]
cbuilara should now be muted
15:02:07 [SteveH]
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15:02:14 [AxelPolleres]
scribe: steveH
15:02:21 [AxelPolleres]
chair: Axel Polleres
15:02:35 [AxelPolleres]
15:02:53 [AxelPolleres]
regrets: LeeF, Chime
15:03:12 [Zakim]
15:03:15 [AxelPolleres]
topic: admin
15:03:20 [bglimm]
Zakim, mute me
15:03:20 [Zakim]
bglimm should now be muted
15:03:24 [AxelPolleres]
PROPOSED: Approve minutes at
15:03:59 [AxelPolleres]
RESOLVED: Approve minutes at
15:04:10 [AxelPolleres]
topic: comments
15:04:32 [SteveH]
Axel: I've updated the comments page, picked any additional comments found on list
15:04:48 [SteveH]
... have several things not assigned, 1 from Greg R, from 26th of Jan
15:05:02 [SteveH]
... not sure if there was an overall answer
15:05:10 [SteveH]
... Lee thinks he's ok with the answer
15:05:17 [SteveH]
... Axel to check with Lee
15:05:42 [SteveH]
... next comment from Jeremy C. on Update, graph identification
15:05:52 [SteveH]
... using URIs that are IRI
15:06:03 [SteveH]
... I will ask Chime if noone else wants to comment
15:06:28 [SteveH]
next, some comment on AVG() testcase from Jeen B
15:06:43 [AxelPolleres]
15:06:45 [SteveH]
Axel: anybody voluneering?
15:07:06 [SteveH]
I guess I should, but I'm really busy
15:07:40 [SteveH]
Axel: I'll put Steve's name on it
15:07:56 [SteveH]
... we should clear all the comments before going to last call
15:07:56 [NickH]
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15:08:05 [AxelPolleres]
ACTION: Steve to draft an answer for JB-4
15:08:05 [trackbot]
Created ACTION-401 - Draft an answer for JB-4 [on Steve Harris - due 2011-03-08].
15:08:24 [alex_]
alex_ has joined #sparql
15:08:51 [SteveH]
Axel: last comment from ???, I can take a look at that
15:08:59 [AxelPolleres]
ACTION: Axel to take care of RV-7
15:08:59 [trackbot]
Created ACTION-402 - Take care of RV-7 [on Axel Polleres - due 2011-03-08].
15:09:04 [SteveH]
??? = Rob V.
15:09:04 [AxelPolleres]
15:09:14 [Zakim]
15:09:38 [AxelPolleres]
15:09:59 [SteveH]
Axel: one problem with comment from Jeen which we can't address yet
15:10:07 [SteveH]
... there's a mail about it on list
15:10:40 [SteveH]
... Jeen commented on MINUS v's NOT EXIST
15:10:44 [AxelPolleres] ... not exists vs. minus
15:10:53 [SteveH]
... don't know how to proceed there
15:11:13 [kasei]
that isn't true, though
15:11:16 [SteveH]
... Jeen says that MINUS is equiv. in all cases where it's not redundant
15:11:38 [Zakim]
15:12:03 [AxelPolleres]
15:12:16 [Zakim]
15:12:24 [SteveH]
Zakim, ??P11 is me
15:12:24 [Zakim]
+SteveH; got it
15:12:52 [SteveH]
kasei: Jeen posted it on his weblog before this comment, and I commented on the blog
15:13:28 [AxelPolleres]
ACTION: greg to answer to with counterexample to JB-2
15:13:28 [trackbot]
Created ACTION-403 - Answer to with counterexample to JB-2 [on Gregory Williams - due 2011-03-08].
15:13:58 [AxelPolleres]
Next regular meeting: 2011-03-08 @ 15:00 UK / 10:00 EST (scribe: Paul Gearon)
15:14:18 [AxelPolleres]
regrets for next week from me
15:14:30 [SteveH]
AxelPolleres: I will not be here but lee will be
15:14:31 [OlivierCorby]
regrets also
15:14:40 [SteveH]
... geosparql has asked us for a review
15:14:49 [AxelPolleres]
topic: gepsparql review
15:15:05 [SteveH]
MattPerry: we have a group of about 10, working on geosparql, it is straightforward, vocab + filter functions for SPARQL
15:15:30 [SteveH]
... in OGC they've had std. object models for geometry, takes on and created RDF vocab that does the same thing
15:15:45 [SteveH]
... different classes for polygon,. point, line + dimensions and so on
15:16:07 [SteveH]
... also functions for objects, created analagous filter functions for them
15:16:15 [SteveH]
... union intersection etc.
15:16:24 [SteveH]
... translation of existing standard
15:16:37 [SteveH]
.... serialise these geometries in RDF, created datatypes
15:16:40 [AxelPolleres]
15:16:57 [SteveH]
... existing text based standards can be put in literals
15:17:23 [SteveH]
... use these literals as arguments to functions
15:18:21 [cbuilara]
I can do it, or ask anybody in my grpup
15:18:25 [cbuilara]
15:18:34 [cbuilara]
zakim, unmunte me
15:18:34 [Zakim]
I don't understand 'unmunte me', cbuilara
15:18:44 [cbuilara]
zakim, unmunte me
15:18:44 [Zakim]
I don't understand 'unmunte me', cbuilara
15:18:54 [cbuilara]
zakim, unmute me
15:18:54 [Zakim]
cbuilara should no longer be muted
15:19:19 [SteveH]
cbuilara: people in my research group working on GML(?)
15:19:25 [SteveH]
... it would be worth them looking at it
15:19:47 [SteveH]
... I will send a review
15:19:54 [AxelPolleres]
ACTION: carlos to look in his group for a review for GeoSPARQL and send it to us
15:19:54 [trackbot]
Could not create new action (failed to parse response from server) - please contact sysreq with the details of what happened.
15:19:54 [trackbot]
Could not create new action (unparseable data in server response: local variable 'd' referenced before assignment) - please contact sysreq with the details of what happened.
15:20:16 [SteveH]
AxelPolleres: to last call...
15:20:23 [SteveH]
... take a look at status of drafts
15:20:24 [AxelPolleres]
topic: to last call
15:20:25 [AxelPolleres]
15:20:25 [AxelPolleres]
15:20:43 [bglimm]
Zakim, unmute me
15:20:43 [Zakim]
bglimm should no longer be muted
15:21:09 [bglimm]
I had a few comments on the revised sections
15:22:43 [SteveH]
AndyS: there are 12 markers in doc for things to do, all editorial - Steve can you look at the eval of ToList, not sure it can be removed
15:22:55 [SteveH]
... if people are happy to comment in that state we can go ahead
15:23:04 [AxelPolleres]
andy: 12 editorial markers in the doc at the moment... apart from that, we can go ahead with review
15:23:42 [SteveH]
AxelPolleres: we have reviewers assigned, so can turn to BGP matching
15:23:53 [AxelPolleres]
BGP matching extensions rewording suggestions by Birte
15:24:02 [SteveH]
... has rewording suggestions
15:24:31 [SteveH]
bglimm: the main problem is that terminology is outdated, uses old terminology
15:24:47 [SteveH]
... uses different word from rest of text, not been updated since defintions were tested
15:24:56 [SteveH]
... would like it updated
15:25:17 [SteveH]
... the only thing I suggest is to require that solutions are uniquely satisfied
15:25:26 [SteveH]
... I think it's quite important
15:25:41 [AxelPolleres]
15:25:44 [SteveH]
... doesn't really change any of the semantics
15:26:06 [SteveH]
AndyS: looked through the text, it looked pretty good, was planning on putting that text in
15:26:16 [SteveH]
... there's a couple of points I want to check
15:26:36 [SteveH]
AxelPolleres: one point, reformulation of cond. 1, sent to list
15:27:08 [SteveH]
[ discussion of uniquely specified issues ]
15:27:41 [Zakim]
15:27:53 [AxelPolleres]
s/uniquely/uniquely (up to RDF graph equivalence)/ ?
15:27:54 [SteveH]
sorry, something wrong with the sip connection :(
15:28:13 [Zakim]
15:28:19 [SteveH]
Zakim, ??P11 is me
15:28:19 [Zakim]
+SteveH; got it
15:29:02 [SteveH]
15:29:44 [SteveH]
15:29:46 [pgearon]
I can try
15:30:01 [SteveH]
AxelPolleres: no action here
15:31:23 [AxelPolleres]
ACTION: Birte to draft xml for revised Extending BGP matching section for query
15:31:23 [trackbot]
Created ACTION-405 - Draft xml for revised Extending BGP matching section for query [on Birte Glimm - due 2011-03-08].
15:31:38 [SteveH]
... that's all for query
15:31:55 [SteveH]
... for update, any news? lots of discussion, will come to that later
15:32:10 [SteveH]
... service descirption, grega, can you give update
15:32:11 [bglimm]
Zakim, mute me
15:32:11 [Zakim]
bglimm should now be muted
15:32:29 [SteveH]
kasei: I've added a couple of things to the SD section, biggest thing is relationship with dataset protocol
15:33:14 [SteveH]
... said I'd take it to email, suggested simple change to SD vocab which will be sufficient to describe a dataset in terms of the dataset protocol
15:33:32 [SteveH]
... if its goes beyond that I'm going to push back, to avoid getting into out of scope things
15:33:37 [SteveH]
... waiting on more discussionm
15:33:57 [SteveH]
... been discussing conformance language with Andy
15:34:16 [SteveH]
... I'm happy discussing on email
15:35:07 [SteveH]
I owe a review on {something}
15:35:10 [bglimm]
Zakim, unmute me
15:35:10 [Zakim]
bglimm should no longer be muted
15:35:23 [SteveH]
bglimm: waiting for a review on entailment
15:35:57 [SteveH]
???: the parital review that was sent out is the final one
15:36:05 [SteveH]
bglimm: I saw one review
15:36:11 [AxelPolleres]
15:36:34 [SteveH]
bglimm: connonicalisation issue
15:36:49 [SteveH]
... only define d-entailment within some limit
15:37:05 [SteveH]
... not happy, but it's what we decided, not sure if we want to revisit
15:37:28 [SteveH]
AxelPolleres: I guess at the moment we just go on, what's your suggestion
15:37:46 [SteveH]
bglimm: I would just remove the entailment, it's not nice that systems behave differently
15:38:09 [SteveH]
... SPARQL doesn't specify this behaviour, so maybe it's not up to the entailments regimes
15:38:48 [SteveH]
... you can only return ansers that occur in the graph, but that depends on parsing process
15:39:04 [SteveH]
... might have two different values, so might return two answers
15:39:22 [AxelPolleres]
issue different answers and also differenct cardinalities implied.
15:39:23 [SteveH]
... can get different cardinality
15:39:40 [SteveH]
... do you want to require canonicalisation - seems to be the only way to solve this problem
15:40:24 [SteveH]
bglimm will add a note to the document
15:40:27 [AndyS]
zakim, who is on the call?
15:40:27 [Zakim]
On the phone I see AndyS, NickH, corby, kasei, pgearon, cbuilara, AxelPolleres, Sandro, MattPerry, bglimm, AlexPassant, SteveH
15:40:32 [AxelPolleres]
15:40:56 [SteveH]
cbuilara: proposed semantics of service algebra, difficult to understand what I was proposing in email, I will follow your comments
15:41:16 [SteveH]
... it is almost finished I think, will be finished this/next week
15:41:44 [SteveH]
formal update semantics]
15:41:51 [AxelPolleres]
topic: Update Formal Semantics (incl. bnodes as DELETE-wildcards)
15:41:53 [SteveH]
particularly bnodes as wildcards
15:41:59 [cbuilara]
zakim, mute me
15:41:59 [Zakim]
cbuilara should now be muted
15:42:25 [SteveH]
AxelPolleres: summary - there were concerns about update semantics as in current draft
15:42:28 [AxelPolleres]
15:42:48 [SteveH]
... because it doesn't cover the resolution that we wanted to create blank nodes in delete patters as wildcards
15:42:57 [SteveH]
... there were some mails with suggestions
15:42:59 [AxelPolleres]
15:43:19 [AxelPolleres]
15:43:19 [SteveH]
... three options
15:43:39 [Zakim]
15:43:52 [Zakim]
15:43:59 [SteveH]
Zakim, ??P0 is me
15:43:59 [Zakim]
+SteveH; got it
15:44:11 [SteveH]
... several coinflip descisions on what it means
15:44:37 [SteveH]
... do the bns match all resources which are available, or whether they are [something]
15:44:43 [SteveH]
... people not so convinced
15:44:55 [SteveH]
... third option is to revisit resolution. no blank nodes as wildcards
15:44:57 [SteveH]
15:46:52 [SteveH]
15:46:55 [AndyS]
15:47:10 [AxelPolleres]
Option 1: Bnode match all resources in the graph (essentially rewriting 1 in the mails)
15:48:12 [AxelPolleres]
Option 2 : bnodes match whatever they match if treated as "moficy_tmeplate copied tyo body"
15:48:39 [AxelPolleres]
(essentially rewriting 2)
15:49:14 [SteveH]
AndyS: are there usecases where 1 & 2 are different
15:49:24 [AxelPolleres]
Option 1 and 2 differ , see
15:51:12 [SteveH]
AxelPolleres: at end of mail there's a simple example, so prolem with unbound is there
15:51:21 [AxelPolleres]
Option3: treat bnodes as in CONSTRUCT/INSERT, i.e. as new bnodes... would mean they don't match anything.
15:51:38 [AxelPolleres]
(that is against our earlier resolution)
15:51:55 [AxelPolleres]
Option4:is to forbid bnodes in DELETE
15:51:55 [AndyS]
15:52:03 [SteveH]
SteveH: rather to make it an error
15:52:18 [SteveH]
AxelPolleres: one mail from birte, not happy with rewritings
15:52:26 [bglimm]
Zakim, unmute me
15:52:26 [Zakim]
bglimm was not muted, bglimm
15:52:50 [SteveH]
bglimm: you could just define that you wanted all things deleteed that are an instance of the graph
15:53:16 [SteveH]
... not specifiy how you want the deletion, reqriting is one way of doing the delete, would like a more abstract definition
15:53:35 [SteveH]
... would have to do some graph matching to decide which triples are deleted
15:53:39 [SteveH]
... re. option 2
15:53:42 [AndyS]
IIUC version 1 does not reflect pattern of bNode use -> makes me v nervious
15:54:21 [SteveH]
... equiv. to option 1, but not specified with UNIONs
15:54:31 [SteveH]
AxelPolleres: think it could be done but not sure anyone has time
15:55:12 [SteveH]
... need some kind of skolemisation/deskolemisation
15:55:25 [AndyS]
Who was a supporter of the original point of making bNodes variables at all? Do we need to check with them?
15:55:34 [SteveH]
bglimm: they are like variables in normal evaluation, don't have to skolemise
15:56:20 [SteveH]
bglimm: think it's more difficult to delete lists
15:56:31 [SteveH]
AndyS: do any of the mechanisms actually help?
15:57:01 [AxelPolleres]
Can someone draft a Testcase that does list deletion?
15:57:05 [SteveH]
bglimm: I think they do
15:57:12 [SteveH]
AndyS: only works where you know the links
15:57:14 [SteveH]
15:57:25 [SteveH]
bglimm: that's the main usecase
15:57:34 [SteveH]
AxelPolleres: only works with fixed length lists
15:59:19 [Zakim]
15:59:37 [Zakim]
15:59:41 [SteveH]
Zakim, ??P0 is me
15:59:41 [Zakim]
+SteveH; got it
16:00:23 [AndyS]
Hmm - something like DELETE { ?x rdf:first ?f ; rdf:rest ?y } WHERE { ?list rdf:rest* ?x . ?x rdf:first ?f ; rdf:rest ?y }
16:00:33 [SteveH]
4, where forbidden = causes an error, rather than bannedby syntax
16:00:34 [bglimm]
3 or 4
16:00:41 [pgearon]
option 4 (followed by 3)
16:00:43 [AndyS]
which works by finding the list element one at a time
16:00:48 [kasei]
16:00:50 [sandro]
(sorry, undecided.)
16:00:54 [AndyS]
no opinion - need to see details.
16:01:02 [OlivierCorby]
don't know yet
16:01:12 [Zakim]
16:01:15 [AxelPolleres]
Strawpoll Option1-4 ?
16:01:16 [AxelPolleres]
prefer 1 over 2 , but can live with 3/4
16:01:32 [Zakim]
16:01:33 [MattPerry]
16:01:35 [MattPerry]
16:01:39 [AxelPolleres]
let's take it to email
16:01:40 [Zakim]
16:01:42 [Zakim]
16:01:44 [Zakim]
16:01:48 [Zakim]
16:01:52 [Zakim]
16:01:54 [Zakim]
16:01:55 [AxelPolleres]
steve, can you take care of the minutes? (need to run)
16:01:56 [SteveH]
hm, Zakim over VoIP, not really mature
16:01:58 [Zakim]
16:02:00 [Zakim]
16:02:04 [Zakim]
16:02:09 [AxelPolleres]
rrsagent, make records public
16:02:20 [Zakim]
16:02:22 [Zakim]
SW_(SPARQL)10:00AM has ended
16:02:24 [Zakim]
Attendees were SteveH, AndyS, corby, NickH, kasei, pgearon, AxelPolleres, Sandro, MattPerry, cbuilara, bglimm, AlexPassant
16:02:37 [AxelPolleres]
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16:29:36 [AndyS]
OK - I have an arbitrary length list deletion SPARQL Update :-)
16:30:01 [AndyS]
It uses INSERT and EXISTS! It's a bit like a Turing machine.
16:34:27 [SteveH]
16:34:47 [bglimm]
Nice, Turing machines are good ;-)
16:34:48 [pgearon]
how complex is it?
16:35:15 [AndyS]
Quite complex :-) Just building an every-case example.
16:36:19 [pgearon]
I really hate to suggest this, but does this justify introducing something for list deletion?
16:36:57 [SteveH]
we descided not to do lists
16:37:00 [SteveH]
16:37:09 [pgearon]
16:37:46 [pgearon]
well, if that's the case, then this will deserve an entry into the "Cookbook" for using SPARQL :-)
16:37:47 [SteveH]
you can't (easily) create arbitrary length lists either
16:38:40 [pgearon]
Interesting. What kind of use cases do you have for creating arbitrary length lists?
16:39:12 [pgearon]
like, "find all of property :x on :y and generate a list of them"?
16:46:14 [AndyS]
I doubt there is a good solution without making lists first class objects in RDF.
16:48:13 [SteveH]
16:49:10 [SteveH]
INSERT { <x> :list ?list } WHERE { SELECT (LIST(?x, ?y, ?z) AS ?list) WHERE { .. } }
16:49:14 [SteveH]
or something like that
16:59:05 [iv_an_ru]
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17:09:13 [AndyS]
email sent - I'm sure it can be shortened but the way it's done reflect the problem solving process.
17:34:17 [iv_an_ru]
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19:44:55 [AndyS]
Birte's suggested text is now in rq25.
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