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Chatlog 2009-04-07
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<LeeF> Present: LeeF, Axel, Ivanh, Chime, SteveH, LukeWM, John-l, kasei, ywang4, dnewman, bijan, simon, KjetilK 13:51:58 <trackbot> Meeting: SPARQL Working Group Teleconference 13:51:58 <trackbot> Date: 07 April 2009 14:00:48 <AxelPolleres> scribe: Axel Polleres 14:00:54 <LeeF> Chair: LeeF 14:00:54 <LeeF> Scribenick: AxelPolleres 14:00:58 <AxelPolleres> scribenick: Axel Polleres 14:01:10 <AxelPolleres> topic: Admin 14:02:11 <LeeF> Regrets: ericP, AndyS, AlexP 14:02:49 <AxelPolleres> LeeF: rearrangement on agenda, bijan joining later, so we shuffle a bit 14:02:52 <LeeF> PROPOSED: Approve minutes at http://www.w3.org/2009/sparql/meeting/2009-03-31 14:03:19 <AxelPolleres> no objections. 14:03:28 <LeeF> RESOLVED: Approve minutes at http://www.w3.org/2009/sparql/meeting/2009-03-31 14:04:05 <LeeF> next meeting: 14-April 14:04:09 <LeeF> regrets next time: ivanh, axel 14:04:22 <AxelPolleres> LeeF: next meeting, 14th, regrets ivanh & Axel 14:04:50 <AxelPolleres> ... last teleconf to discuss new features. THen we start with consensus reaching and consolidation. 14:05:05 <KjetilK> Zakim, what is the code? 14:05:05 <Zakim> the conference code is 77277 (tel:+1.617.761.6200 tel:+33.4.89.06.34.99 tel:+44.117.370.6152), KjetilK 14:05:08 <AxelPolleres> ... pls check features to be discussed and send your thoughts! 14:05:21 <AxelPolleres> topic: liaisons 14:05:42 <AxelPolleres> http://www.w3.org/2007/OWL/wiki/InternationalizedStringSpec 14:05:44 <LeeF> Axel: OWL WG and RIF WG discussing rdf:text datatype 14:05:59 <Zakim> + +1.479.864.aaaa 14:06:04 <KjetilK> Zakim, aaaa is me 14:06:04 <Zakim> +KjetilK; got it 14:06:12 <KjetilK> Zakim, mute me 14:06:12 <Zakim> KjetilK should now be muted 14:07:02 <LeeF> Axel: might want SPARQL WG to review last call draft 14:08:05 <AxelPolleres> ACTION: Axel to send a pointer to the mailinglist for rdf:text, when it's up to LC 14:08:08 <trackbot> Created ACTION-7 - Send a pointer to the mailinglist for rdf:text, when it's up to LC [on Axel Polleres - due 2009-04-14]. 14:09:08 <AxelPolleres> LeeF: ControlOfDescribeQueries next week. 14:09:15 <LeeF> topic: Xproc <LeeF> summary: initial straw poll gives (+/0/-): 0/0/13 14:09:18 <LeeF> -> http://lists.w3.org/Archives/Public/public-rdf-dawg-comments/2009Mar/0004.html 14:10:20 <Zakim> +Chimezie_Ogbuji 14:10:39 <SteveH> q+ 14:11:10 <ivanh> -> http://www.w3.org/TR/xproc/ XPROC draft 14:11:54 <AxelPolleres> Lee: looks like more related to RDF Core and XProc WG's. we can't do it alone. 14:12:00 <Zakim> +DaveNewman 14:12:03 <AxelPolleres> q+ 14:12:11 <LeeF> ack SteveH 14:12:38 <AxelPolleres> Steve: on RDF/XML, XProc is solved and no problem. 14:13:13 <LeeF> ack AxelPolleres 14:13:22 <SteveH> ...that's not what I meant 14:13:32 <SteveH> I meant that RDF/XML is not our problem 14:13:34 <AxelPolleres> ... pipes.deri.org 14:13:55 <ivanh> q+ 14:13:55 <dnewman2> dnewman2 has joined #sparql 14:14:00 <LeeF> AxelPolleres: DERI working on pipes tool - workflow for RDF, includes SPARQL - XML serialization, we will align with XProc 14:14:26 <AxelPolleres> xsparql.deri.org 14:15:22 <LeeF> LeeF: Does DERI think this is something we should pursue? 14:15:42 <LeeF> AxelPolleres: Not in the core of our charter, would be better joint with XProc or XQuery folks, maybe people volunteering as a note 14:15:46 <LeeF> ack ivanh 14:16:29 <AxelPolleres> (those comments chairhat-offf) 14:17:04 <AxelPolleres> Leef: strawpoll on Xproc?? 14:16:38 <ivanh> -1 14:16:40 <KjetilK> -1 (out of scope) 14:16:41 <SteveH> -1, not our problem 14:16:41 <ywang4> -1 14:16:43 <john-l> -1 14:16:44 <kasei> -1 14:16:44 <ywang4> -1 14:16:44 <chimezie> -1 14:16:44 <LukeWM> -1 14:16:46 <AxelPolleres> ivanh: also think that this is not in the charter. 14:16:50 <SimonS> -1 out of scope 14:16:54 <dnewman2> -1 14:16:55 <LeeF> -1 14:17:12 <AxelPolleres> -1 out of scope 14:17:29 <LeeF> topic: XML literal results <LeeF> summary: initial straw poll gives (+/0/-): 1/5/6 14:17:30 <LeeF> http://lists.w3.org/Archives/Public/public-rdf-dawg-comments/2009Mar/0022.html 14:18:19 <SteveH> q+ to ask about XML Schema 14:18:27 <AxelPolleres> LeeF: xml literals in results are currently encoded/escaped in SPARQL results. 14:18:41 <AxelPolleres> ... proposed here is unescaped XML in results 14:19:11 <LeeF> -> http://lists.w3.org/Archives/Public/public-rdf-dawg/2007JulSep/0163.html EricP 14:19:53 <AxelPolleres> ... probably no implementation does it right now, but probably just because it is not compliant. 14:20:06 <LeeF> ack SteveH 14:20:06 <Zakim> SteveH, you wanted to ask about XML Schema 14:20:35 <ivanh> q+ 14:20:47 <AxelPolleres> steve: that would push us out of XML sparql result XSD. 14:21:04 <AxelPolleres> Lee: we could using any content, but that's probably not helpful. 14:21:24 <AxelPolleres> q+ to ask about anytype in XML schema 14:21:38 <LeeF> ack ivanh 14:22:04 <AxelPolleres> ivanh: issues around schema and RDF/XML were more complex than that. 14:22:20 <AxelPolleres> ... has there been a user request in this respect? 14:23:13 <LeeF> ack AxelPolleres 14:23:13 <Zakim> AxelPolleres, you wanted to ask about anytype in XML schema 14:24:58 <AxelPolleres> Axel: seems doable in XML Schema 14:25:19 <AxelPolleres> Lee: but not very helpful, w/o a mechanism to also specify which XML schema is meant there. 14:25:20 <SteveH> -1, too complex 14:25:22 <KjetilK> +1 (if the submitter can justify it further, I much prefer XML to be addressable with XPath) 14:25:26 <kasei> 0 14:25:27 <ivanh> -1 priorities 14:25:28 <ywang4> -1 14:25:30 <chimezie> -1 low priority 14:25:33 <john-l> 0 14:25:35 <AxelPolleres> ... strawpoll on allowing unescaped XML? 14:25:35 <LukeWM> -1 14:25:38 <AxelPolleres> 0 14:25:40 <dnewman2> 0 14:25:40 <SimonS> -1 14:25:40 <LeeF> 0 14:26:24 <KjetilK> Zakim, unmute me 14:26:24 <Zakim> KjetilK should no longer be muted 14:27:51 <AxelPolleres> Kjetil: sees potential in XML in results for being XPath processable. Likes to postpone this, because we may be talking about different things here, needs clarification. 14:28:01 <AxelPolleres> ... next week problematic for me. 14:28:53 <AxelPolleres> s/this,/ControlOfDescribeQueries,/ 14:29:04 <LeeF> http://lists.w3.org/Archives/Public/public-rdf-dawg/2009AprJun/0004.html 14:29:17 <KjetilK> Zakim: mute me 14:29:21 <LeeF> topic: SurfaceSyntax <LeeF> summary: initial straw poll give (+/0/-): 10/3/0 (much support "time permitting") 14:29:25 <AxelPolleres> LeeF: let's look at surface syntax 14:29:34 <LeeF> http://www.w3.org/2009/sparql/wiki/Feature:SurfaceSyntax 14:30:37 <AxelPolleres> ... this is about "syntactic sugar" to be definable in terms of the current spec. 14:32:39 <AxelPolleres> ... assignments, evaluated expressions partially overlap. 14:32:52 <AxelPolleres> ... scalarExpressions. 14:33:09 <ivanh> q+ 14:33:20 <AxelPolleres> ... my idea is treating these at once. 14:33:20 <SteveH> q+ 14:33:23 <AxelPolleres> q+ 14:33:27 <LeeF> ack ivanh 14:33:45 <AxelPolleres> ivanh: these are low-priority things. 14:33:55 <LeeF> q+ to note educational / learning aspect 14:34:42 <LeeF> ack SteveH 14:34:49 <AxelPolleres> ivanh: syntactic sugar may give impression of huge changes, where there aren't 14:35:10 <AxelPolleres> steve: agree with ivanh mostly. 14:35:44 <KjetilK> q+ 14:36:23 <dnewman2> +q 14:36:25 <LeeF> ack AxelPolleres 14:36:27 <AxelPolleres> ... we should avoid "syntactic nightmare" extension 14:36:44 <SteveH> "syntactic nightmare" lack of extension, really 14:37:23 <LeeF> ?s :p `3 + 4` 14:37:40 <SteveH> you can't do that with a filter... 14:37:41 <LeeF> ?s :p `?o + 4` 14:37:45 <Zakim> +??P6 14:37:49 <bijan> zakim, ??P6 is me 14:37:49 <Zakim> +bijan; got it 14:37:52 <bijan> zakim, mute me 14:37:52 <Zakim> bijan should now be muted 14:38:44 <LeeF> q? 14:39:52 <LeeF> ack LeeF 14:39:52 <Zakim> LeeF, you wanted to note educational / learning aspect 14:40:12 <AxelPolleres> LeeF: scalar in construct could be a synt sugar subfeature of assignment. 14:40:30 <bijan> I'll note that good surface syntax can reveal optimization oppourtunities 14:40:32 <AxelPolleres> ... that is why I count it in "surface syntax" 14:40:45 <LeeF> ack KjetilK 14:41:23 <AxelPolleres> Kjetil: we shouldn't under-estimate the power of writing things quickly. 14:41:28 <SteveH> Garlik use ?x = ... || ?x = ... a lot 14:41:55 <chimezie> We also have had numerous requests for IN support 14:42:00 <LeeF> ack dnewman 14:42:02 <AxelPolleres> ... IN is an axemaple of that. 14:42:24 <AxelPolleres> dave: from an end user perspective this is very attractive. 14:42:48 <AxelPolleres> ... aligns in certain respects with SQL. would support it. 14:43:05 <AxelPolleres> LeeF: any othe opinions? 14:43:19 <ivanh> 0 14:43:20 <KjetilK> +1 (but, yeah, lets do it at the end) 14:43:23 <bijan> 0 14:43:24 <SteveH> 0, it's too broad 14:43:25 <kasei> +1 14:43:26 <chimezie> +1 14:43:27 <dnewman2> +1 14:43:29 <SimonS> +1 agree with Kjetil and Dave, do it at the end 14:43:36 <john-l> 0 14:43:39 <LukeWM> +1 for at the end 14:43:39 <AxelPolleres> strawpoll: is work on surface syntax in general in scope of the WG? 14:43:45 <LeeF> +1 time permitting 14:43:51 <KjetilK> Zakim, mute me 14:43:51 <Zakim> KjetilK should now be muted 14:43:51 <AxelPolleres> +1 14:43:53 <ywang4> +1 14:44:07 <SteveH> +1, time permitting, probably 14:44:08 <ywang4> and i think it should be a bit more 14:44:29 <AxelPolleres> (obvious and consensual surface syntax features only) 14:44:39 <bijan> zakim, unmute me 14:44:39 <Zakim> bijan should no longer be muted 14:44:54 <LeeF> topic: SPARQL/OWL <LeeF> summary: initial straw poll gives (+/0/-): 7/5/0 14:44:55 <LeeF> http://www.w3.org/2009/sparql/wiki/Feature:SPARQL/OWL 14:44:58 <AxelPolleres> topic: sparql/owl 14:45:51 <AxelPolleres> bijan: a document which specifies which additional inferneces/answers on BGP patterns you should get under various OWL/OWL2 entailment regimes 14:45:53 <ivanh> q+ 14:46:15 <AxelPolleres> LeeF: would we do it for one flavor of OWL? 14:46:49 <AxelPolleres> Bijan: my goal would be conjunctive queries. tend to look on existing implementations and reflect what they DO. 14:46:52 <AxelPolleres> q+ 14:47:14 <AxelPolleres> ... with as much OWL as they can possibly handle 14:48:17 <AxelPolleres> ... kaon2 supports SPARQL with non-distiguished variables, over OWL2 w/o nominals, pellet supports all of SPARQL, Hermit will support as much as KOAN2. 14:48:20 <chimezie> q+ about relationship with general specification of entailment 14:48:27 <chimezie> q+ 14:48:37 <AxelPolleres> ... racer pro supports NRQL, overlaps greatly with SPARQL. 14:49:09 <KjetilK> q+ 14:49:11 <LukeWM> q+ 14:49:13 <AxelPolleres> ... Quonto is an OLWLQL implementation, OWLGraph supports SPARQL. 14:49:23 <LeeF> ack ivanh 14:49:47 <AxelPolleres> ivanh: what is the different in semantics we are talking about? 14:50:05 <LeeF> -> http://www.w3.org/TR/rdf-sparql-query/#sparqlBGPExtend Extending SPARQL Basic Graph Pattern Matching 14:50:20 <AxelPolleres> bijan: achievable goal is: if you turn on inference, you get more answers. 14:50:47 <AxelPolleres> ... it is not entirely clear ore desirable. certain meta-modeling in RDF are impossible to implement. 14:51:09 <AxelPolleres> ... e.g. redefining rdf:type. 14:51:49 <AxelPolleres> ... trey to restrict myself on queries that are reasonable in terms of both OWL and RDF. 14:52:25 <Zakim> -ywang4 14:52:35 <ywang4> gonna leave, cheers 14:52:42 <AxelPolleres> ivanh: are all queries you send to a OWL reasoner encodable in SPARQL or not? 14:52:44 <LeeF> take care, ywang4 14:52:53 <LeeF> see you next week 14:53:00 <AxelPolleres> bijan: standard conjunctive queries yes fully covered by SPARQL. 14:53:09 <ywang4> see you guys :) 14:53:14 <ywang4> ywang4 has left #sparql 14:53:15 <AxelPolleres> ... SPARQL intuitivelty also allows asking about the SCHEMA. 14:53:34 <AxelPolleres> ... I think we can get a reasonable fraction of that. 14:53:51 <AxelPolleres> ivanh: how much work and energy will it take? 14:54:08 <AxelPolleres> bijan: mostly done from a paper I have, technically not difficult, transfer to spec. 14:54:09 <LeeF> ack AxelPolleres 14:55:04 <LeeF> ack chimezie 14:55:32 <AxelPolleres> Axel: linking,describing that on the wiki on the feature page, also that summary you gave would be extremly helpful. 14:56:30 <AxelPolleres> bijan: schema queries doable to some extent, standard syntax for that. 14:57:09 <AxelPolleres> bijan: use that entailment in queries qwould be something to standardize. 14:57:38 <AxelPolleres> q+ 14:58:21 <AxelPolleres> Leef: mechanism to know which entailment is "done" 14:58:23 <ivanh> q+ 14:58:37 <LeeF> ack KjetilK 14:59:11 <chimezie> I'm wondering whether we can afford to do both this proposal as well as something like ParameterizedInference (which seems like the general case) 14:59:17 <AxelPolleres> kjetil: implementations that do simple bw-chaining, would that proposal influence them? 14:59:30 <chimezie> or whether there is overlap between the two 15:00:11 <AxelPolleres> bijan: OWL has an OWL RL subprofile implementable in rules, QL implementable by rule expansion, OWL EL implementable in combination 15:00:31 <ivanh> q- 15:00:36 <AxelPolleres> ... not sure whether this is answering your question. 15:01:12 <AxelPolleres> kjetil: would it cover to know "which profile is used by a certain engine"? 15:01:29 <KjetilK> Zakim, mute me 15:01:29 <Zakim> KjetilK should now be muted 15:01:33 <LeeF> ack LukeWM 15:01:37 <AxelPolleres> bijan: tell what you have is a separate issue 15:02:03 <kasei> bijan: based on the sparql-dl paper, it seems that you define a ast->triples conversion, but I didn't see the (presumably desirable) sparql syntax->ast conversion. 15:02:31 <LeeF> ack AxelPolleres 15:03:10 <LeeF> AxelPolleres: is bnode coreference solved? 15:03:20 <LeeF> bijan: persists as an open issue, think I have a reasonable solution 15:03:50 <LeeF> ... think best way to get interoperability is to treat bnodes as local names 15:04:07 <ivanh> q+ 15:04:22 <LeeF> zakim, close the queue 15:04:22 <Zakim> ok, LeeF, the speaker queue is closed 15:05:02 <LeeF> AxelPolleres: in terms of metaqueries, would you restrict certain queries? 15:05:27 <LeeF> bijan: two possibilies. 1) might need to restrict queries. 2) restrict answers, so e.g. if ?C subclass ?D 15:05:32 <LeeF> ... you could restrict answers to atomic classes only 15:05:37 <LeeF> ... to avoid infinite trivial answers 15:06:33 <SimonS> +q to ask whether syntactic restrictions are possible in SPARQL1 entailment regimes 15:07:13 <LeeF> bijan: algebra stays the same, it does operations on a tuple level 15:07:40 <AxelPolleres> ... only BGP. 15:08:32 <LeeF> ivanh: do any other features affect this? 15:08:39 <LeeF> bijan: i don't think so since none of them trouch BGP matching semantics 15:08:56 <LeeF> ivanh: would this be a separate document? 15:08:58 <LeeF> bijan: yes 15:09:57 <LeeF> SimonS: is it possible to restrict syntax within an entailment regime? 15:10:21 <LeeF> bijan: you can implement this by saying that for queries that you think are syntactically malformed you return nothing 15:11:10 <bijan> +1 15:11:11 <ivanh> 1 (with the hope it will work out:-) 15:11:15 <KjetilK> +1 (since it is allready almost there, and it covers the simple stuff) 15:11:16 <LukeWM> 0 15:11:22 <dnewman2> +0 15:11:23 <LeeF> zakim, who's here? 15:11:23 <Zakim> On the phone I see john-l, kasei (muted), ivanh, AxelPolleres, Lee_Feigenbaum, ??P24, SimonS, KjetilK (muted), Chimezie_Ogbuji, DaveNewman, bijan 15:11:25 <SimonS> +1 15:11:26 <Zakim> ??P24 has SteveH, LukeWM 15:11:27 <Zakim> On IRC I see dnewman2, LukeWM, SteveH, ivanh, RRSAgent, chimezie, kasei, AxelPolleres, bijan, SimonS, LeeF, KjetilK, iv_an_ru, Zakim, trackbot, john-l, ericP 15:11:29 <john-l> 0 15:11:33 <kasei> +1 15:11:35 <LeeF> +1 15:11:45 <chimezie> 0 (I still don't have a grasp on the relationship between this feature and the other entailment features requests) 15:11:46 <SteveH> 0, I like, but my org has no use for it sadly 15:11:52 <AxelPolleres> 0.5 thinking that this is only solvable in cinjunciton with Param Inference and need to get clearer about the issues. 15:12:08 <AxelPolleres> +1 (but in principle positive... ok) 15:12:12 <AxelPolleres> ok ok ok ;-) 15:12:20 <chimezie> bijan: okay I will :) 15:13:40 <LeeF> Encourage discussion of other features on the mailing list <LeeF> Adjourned. # SPECIAL MARKER FOR CHATSYNC. 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