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Chatlog 2010-03-09
From SPARQL Working Group
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14:50:26 <RRSAgent> RRSAgent has joined #sparql 14:50:26 <RRSAgent> logging to http://www.w3.org/2010/03/09-sparql-irc 14:50:28 <trackbot> RRSAgent, make logs world 14:50:28 <Zakim> Zakim has joined #sparql 14:50:30 <trackbot> Zakim, this will be 77277 14:50:30 <Zakim> ok, trackbot; I see SW_(SPARQL)10:00AM scheduled to start in 10 minutes 14:50:31 <LeeF> zakim, this will be SPARQL 14:50:31 <trackbot> Meeting: SPARQL Working Group Teleconference 14:50:31 <trackbot> Date: 09 March 2010 14:50:32 <Zakim> ok, LeeF; I see SW_(SPARQL)10:00AM scheduled to start in 10 minutes 14:50:33 <LeeF> Chair: LeeF 14:50:38 <LeeF> Scribe: Souri 14:50:44 <LeeF> Agenda: http://www.w3.org/2009/sparql/wiki/Agenda-2010-03-09 14:53:11 <AlexPassant> AlexPassant has joined #sparql 14:55:36 <Zakim> SW_(SPARQL)10:00AM has now started 14:55:42 <Zakim> +??P0 14:55:47 <AndyS> zakim, ??P0 is me 14:55:47 <Zakim> +AndyS; got it 14:57:08 <MattPerry> MattPerry has joined #sparql 14:58:17 <bglimm> bglimm has joined #sparql 14:58:26 <Zakim> +MattPerry 14:59:15 <Zakim> +kasei 14:59:23 <kasei> Zakim, mute me 14:59:23 <Zakim> kasei should now be muted 15:00:09 <ivan> zakim, dial ivan-voip 15:00:09 <Zakim> ok, ivan; the call is being made 15:00:11 <Zakim> +Ivan 15:00:30 <tommik> tommik has joined #sparql 15:00:34 <Zakim> +bglimm 15:00:42 <bglimm> Zakim, mute me 15:00:42 <Zakim> bglimm should now be muted 15:01:09 <Zakim> + +035840564aaaa 15:01:19 <tommik> zakim, aaaa is me 15:01:19 <Zakim> +tommik; got it 15:01:26 <Zakim> +LeeF 15:01:40 <LeeF> zakim, who's on the phone? 15:01:40 <Zakim> On the phone I see AndyS, MattPerry, kasei (muted), Ivan, bglimm (muted), tommik, LeeF 15:01:59 <AndyS> Hi all. 15:02:17 <Zakim> +??P19 15:02:21 <AlexPassant> Zakim, ??P19 is me 15:02:21 <Zakim> +AlexPassant; got it 15:02:34 <AxelPolleres> AxelPolleres has joined #sparql 15:02:38 <LeeF> Scribe: MattPerry 15:02:41 <LeeF> Scribenick: MattPerry 15:02:46 <LeeF> Regrets+ Souri 15:03:01 <Zakim> +dcharbon2 15:03:18 <LeeF> PROPOSED: Approve minutes at http://www.w3.org/2009/sparql/meeting/2010-03-02 15:03:59 <LeeF> RESOLVED: Approve minutes at http://www.w3.org/2009/sparql/meeting/2010-03-02 15:04:23 <SteveH> SteveH has joined #sparql 15:04:32 <SteveH> hi all 15:04:34 <LeeF> Next meeting: 2010-03-16 @ 14:00 UK / 10:00 EDT 15:05:04 <ivan> possible regrets for me 15:05:26 <MattPerry> LeeF: 2 weeks of 4 hr difference 15:05:31 <Zakim> + +0207735aabb 15:05:43 <SteveH> Zakim, aabb is me 15:05:43 <Zakim> +SteveH; got it 15:06:49 <MattPerry> LeeF: may be a problem that Paul is not here ... but we will try to make decisions anyway 15:07:13 <LeeF> http://lists.w3.org/Archives/Public/public-rdf-dawg/2010JanMar/0428.html 15:07:27 <MattPerry> Topic: Blank Nodes in Delete 15:08:01 <MattPerry> Option 1: no blank nodes in delete template 15:08:16 <MattPerry> Option 2: blank nodes as wildcard in delete template 15:09:56 <MattPerry> LeeF: if prohibit blank nodes now can we change it later 15:10:16 <Zakim> +AxelPolleres 15:10:47 <bglimm> Zakim, unmute me 15:10:47 <Zakim> bglimm should no longer be muted 15:11:09 <AndyS> I don't understand why if we exclude bnode syntax now we are effectively deciding for the future. 15:11:22 <LeeF> AndyS, yes, that's what I was trying to say 15:11:28 <MattPerry> bglimm: can live with no blank nodes but would be better with them 15:11:31 <ivan> q+ 15:11:37 <LeeF> ack ivan 15:12:26 <SteveH> q+ 15:12:31 <bglimm> q+ to ask about deleting lists without allowing bnodes 15:12:33 <LeeF> ack SteveH 15:12:34 <MattPerry> ivan: there are non-entailment related use cases that need blank nodes 15:13:30 <LeeF> DELETE { ?x :hasList (1 2 3) } WHERE { ... ?x } 15:13:35 <AxelPolleres> (just to be able to follow... what is discussed - said by ivan - is that not allowing to "delete bnodes" would not allow to delete lists? 15:14:24 <LeeF> ack bglimm 15:14:24 <Zakim> bglimm, you wanted to ask about deleting lists without allowing bnodes 15:14:45 <MattPerry> SteveH: rdf list blank node shortcut doesn't add new functionality just makes it easier 15:14:48 <ivan> q+ 15:14:50 <bglimm> ack bglimm 15:14:58 <AxelPolleres> what does this mean if the data graph has two lists (1 2 3) as value of :hasList ? (with different bnode ids?) 15:15:41 <AxelPolleres> q+ 15:16:08 <ivan> ack ivan 15:16:15 <AxelPolleres> q+ to ask whether the vars in the DELETE template don't need to be bou�nd in the WHERE 15:16:36 <LeeF> ack ivan 15:16:41 <SteveH> q+ 15:17:16 <AxelPolleres> ack axel 15:17:16 <Zakim> AxelPolleres, you wanted to ask whether the vars in the DELETE template don't need to be bou�nd in the WHERE 15:17:17 <LeeF> ack AxelPolleres 15:17:50 <LeeF> ack SteveH 15:17:59 <MattPerry> LeeF: long var-based list expression must be repeated in both Delete and Where 15:18:40 <MattPerry> SteveH: can you use property paths to get list variables? 15:18:48 <AxelPolleres> so, just to note, such a delete would indeed all the matching lists (answering my own question from further above) 15:19:37 <LeeF> straw poll: preference between (1) prohibiting blank nodes in DELETE templates and (2) blank nodes in DELETE templates act as wild cards 15:19:44 <ivan> q+ 15:19:54 <AndyS> Wheer are we on need "all triples must match" rule -- else chaos may result (half a list goes if wrong length) 15:19:55 <LeeF> ack ivan 15:20:12 <MattPerry> ivan: also same blank node cannot be in both delete and where 15:20:15 <kasei> q+ 15:20:18 <AndyS> Pref: 2 15:20:20 <bglimm> 2 15:20:23 <kasei> Zakim, unmute me 15:20:23 <Zakim> kasei should no longer be muted 15:20:23 <ivan> Pref: 2 15:20:25 <LeeF> ack kasei 15:20:32 <SteveH> pref: 1, but 2 probably ok 15:20:37 <MattPerry> Pref: 2 15:21:13 <ivan> q+ 15:21:17 <MattPerry> kasei: can rdf list be a special case? 15:21:23 <AxelPolleres> slight pref 2, still don't feel sure about implications 15:21:55 <MattPerry> kasei: grammar can enforce this 15:22:11 <LeeF> ack ivan 15:22:13 <MattPerry> LeeF: specification still needs to give semantics for blank nodes 15:22:25 <kasei> Zakim, mute me 15:22:25 <Zakim> kasei should now be muted 15:22:38 <LeeF> My preference is for #1 15:22:50 <MattPerry> ivan: many cases for blank nodes beyond rdf lists 15:23:00 <AxelPolleres> q+ to note that conceptually, it seems strange, since it would be the only place where bnodes have a "universal variables" meaning, whereas anywhere alse they rather indicate "existential variables" 15:23:19 <AxelPolleres> ... but I have no better proposal 15:23:27 <LeeF> ack AxelPolleres 15:23:27 <Zakim> AxelPolleres, you wanted to note that conceptually, it seems strange, since it would be the only place where bnodes have a "universal variables" meaning, whereas anywhere alse they 15:23:27 <AndyS> but they are bnodes in the data. a ?var can be bound to a data bnode 15:23:31 <Zakim> ... rather indicate "existential variables" 15:24:00 <bglimm> I think in my examples you could always use the [] notation and as I understand it, that would be allowd even under 1 15:24:42 <bglimm> and Steve 15:25:06 <AndyS> opt 1 bans [] in delete template AIUI 15:25:07 <SteveH> I'm about -0.5 15:25:30 <LeeF> PROPOSED: Blank nodes in DELETE templates act as "wild cards", effectively as variables bound to all RDF terms; the same blank node cannot be used in the WHERE clause and the template, or in multiple BGPs 15:26:03 <kasei> +1 15:26:05 <ivan> second it 15:26:06 <bglimm> +1 15:26:07 <ivan> +1 15:26:16 <SteveH> abstain 15:26:20 <dcharbon2> abstain 15:26:42 <LeeF> RESOLVED: Blank nodes in DELETE templates act as "wild cards", effectively as variables bound to all RDF terms; the same blank node cannot be used in the WHERE clause and the template, or in multiple BGPs, SteveH, dcharbon2, LeeF abstaining 15:26:50 <AxelPolleres> +1 (lacking better solutions) 15:27:28 <LeeF> http://www.w3.org/2009/sparql/track/issues/51 15:27:28 <MattPerry> Topic: Data Sets in SPARQL Update 15:27:40 <SteveH> [[[ 15:27:41 <SteveH> something like: 15:27:43 <SteveH> DELETE { ?n rdf:first ?f ; rdf:rest ?n } 15:27:43 <SteveH> WHERE { <list> rdf:first*/rdf:rest* ?n . ?n rdf:first ?f ; rdf:next ?n } 15:27:44 <SteveH> ]]] 15:30:07 <MattPerry> LeeF: SPARQL query allows specification of an RDF Dataset, but SPARQL update does not allow query to select specific RDF Dataset 15:30:33 <SteveH> q+ 15:30:49 <AndyS> Is this different from using GRAPH in the pattern? 15:31:00 <SteveH> GRAPH ?g ... FILTER(?g = <a> || ...) 15:31:24 <MattPerry> LeeF: what is the scope of graphs that the WHERE is matched against? 15:31:35 <AndyS> If the default dataset is changed (to some union using FROM...), it goes make a difference. 15:32:19 <MattPerry> LeeF: No way to give default graph for update 15:32:28 <AndyS> q+ to ask how does this interact with WITH? 15:32:30 <LeeF> q? 15:32:33 <LeeF> ack SteveH 15:33:02 <ivan> Lees' syntax example: INSERT INTO <g1> { template } FROM g2 FROM g3 FROM NAMED g4 FROM NAMED 15:33:02 <ivan> g5 WHERE { GRAPH ?g { ?s ?p ?o } } 15:33:10 <LeeF> SELECT ... FROM <g1> FROM <g2> { tp1 . tp2 } 15:33:51 <LeeF> SELECT ... { GRAPH ?g1 { tp1 } . GRAPH ?g2 { tp2 } } 15:34:16 <MattPerry> LeeF: can do this with GRAPH but WHERE gets very complicated 15:34:17 <AndyS> not quite - tp may span g1 and g2. 15:34:34 <LeeF> AndyS, one tp can span two graphs? 15:34:37 <LeeF> q? 15:34:39 <LeeF> ack AndyS 15:34:39 <Zakim> AndyS, you wanted to ask how does this interact with WITH? 15:34:57 <AxelPolleres> SELECT ... { GRAPH ?g1 { tp1 } . GRAPH ?g2 { tp2 } } FILTER (?g1 = <g1> or ?g1= <g2> and ?g2 = <g1> or ?g2= <g2> ) 15:34:59 <AxelPolleres> ? 15:35:36 <LeeF> AxelPolleres, right 15:35:37 <AndyS> tp1 can match g1 or g2, tp2 can match g1 or g2 => 4 cases 15:35:37 <LeeF> q? 15:35:50 <AndyS> (bnodes ... :-)) 15:36:12 <AxelPolleres> q+ 15:36:22 <AndyS> I'm happy to consider the design. Seems harmless (so far). 15:36:54 <AndyS> I can see that WITH != FROM (WITH is the updated graph, FROM is the queried graph) 15:37:08 <LeeF> ack AxelPolleres 15:38:12 <AndyS> Can't update a synthetic graph (e.g. merge of 2 graphs) 15:38:27 <LeeF> q? 15:38:39 <AndyS> LeeF, your suggestion is good. 15:39:01 <MattPerry> LeeF: interaction of WITH and FROM needs more investigation 15:39:16 <AxelPolleres> I see a problem with e.g. INSERT { ?X p ?Y } FROM <g1> FROM <g2> WHERE { ?X p1 o1 . ?Y p2 o2. } 15:40:31 <AxelPolleres> ... don't know what it means. A proposal should make this corner cases clear, before we can really figure out whether/where it is useful. 15:41:09 <LeeF> ACTION: Lee to work with Paul to flesh out design proposal for FROM/FROM NAMED (datasets) in SPARQL Update 15:41:09 <trackbot> Created ACTION-202 - Work with Paul to flesh out design proposal for FROM/FROM NAMED (datasets) in SPARQL Update [on Lee Feigenbaum - due 2010-03-16]. 15:41:45 <LeeF> http://lists.w3.org/Archives/Public/public-rdf-dawg/2010JanMar/0432.html 15:42:00 <MattPerry> Topic: Update Fault Types 15:42:55 <MattPerry> AndyS: with HTTP there are few error codes 15:44:03 <MattPerry> dcharbon2: WSDL 2.0 has no limit on error codes 15:44:06 <dcharbon2> http://www.w3.org/TR/2006/CR-wsdl20-adjuncts-20060327/#http-fault-decl 15:45:41 <Zakim> -AlexPassant 15:45:43 <SteveH> q+ 15:46:09 <LeeF> ACK SteveH 15:49:07 <Zakim> +??P2 15:49:08 <AlexPassant> Zakim, ??P2 is me 15:49:08 <Zakim> +AlexPassant; got it 15:49:22 <MattPerry> LeeF: does it make sense to have a lot of faults if there are only a couple of error codes? 15:50:29 <MattPerry> dcharbon2: could start with 2 basic error codes and see what users think 15:50:30 <kasei> i'd be interested in seeing the use of many of the 2xx http codes be conformant (going beyond the idea of just faults). 202 in particular. 15:51:23 <MattPerry> LeeF: what code does drop non-existent graph map to? 15:51:26 <kasei> 400 bad request seems like a potential status code... 15:51:56 <AndyS> "202 Accepted" is not an error? 2xx are all positives? Text is "Successful 2xx" 15:52:06 <AndyS> ?? "304 Not Modified" 15:52:13 <SteveH> could be 15:52:20 <MattPerry> SteveH: there are many more-specific HTTP codes to use 15:53:10 <MattPerry> LeeF: lets hold off on error codes until update language is set 15:54:02 <MattPerry> AndyS: it is still useful to identify what the possible errors are even though they are not exposed in the SPARQL protocol 15:54:14 <SteveH> +1 to AndyS 15:54:21 <MattPerry> AndyS: informative text can do this 15:55:35 <MattPerry> LeeF: Next week HTTP protocol, Property Paths, what is and is not in update language, and F2F 15:55:49 <Zakim> -bglimm 15:55:50 <Zakim> -SteveH 15:55:50 <Zakim> -LeeF 15:55:50 <Zakim> -AxelPolleres 15:55:53 <Zakim> -kasei 15:55:54 <Zakim> -MattPerry 15:55:56 <Zakim> -dcharbon2 15:55:56 <ivan> zakim, drop me 15:55:56 <Zakim> Ivan is being disconnected 15:55:58 <Zakim> -Ivan 15:55:58 <Zakim> -tommik 15:56:12 <SteveH> it's spooky that zakim knows more of my phone umber than I do :) 15:56:20 <AndyS> zakim, drop me 15:56:20 <Zakim> AndyS is being disconnected 15:56:22 <Zakim> -AndyS 15:58:52 <kasei> can anyone help me parse a sentence from the RDF/XML spec? 15:59:13 <LeeF> kasei, can try :D 15:59:25 <kasei> i'm looking for a URI that identifies RDF/XML, the serialization format. 15:59:33 <kasei> section 5.1 says, "The RDF Vocabulary is identified by this namespace name" 15:59:42 <kasei> I'm trying to sort out if "RDF Vocabulary" is what I'm after. 15:59:51 <kasei> I suspect not, but not totally sure. 15:59:56 <AndyS> no, it's not. 16:00:10 <AndyS> RDF vocab is "rdf:type" etc. 16:00:23 <kasei> bah. annoyed that we've been able to get this far without URIs for some very basic stuff! 16:00:32 <AndyS> Not sure there is a URI for the synatx - is there a URI for every MIME type? 16:01:09 <AndyS> There is naming competition between MIME types and formats ... so not sure if anyone has been bold enough to go there. 16:01:10 <kasei> well, much like the rdf/xml spec, there's probably an offical information resource for mime types, but that's different. 16:01:27 <AndyS> Fairly certain W3C hasn't - would be a nice suprise if they had. 16:01:30 <AndyS> ivan? 16:02:13 <kasei> wonder if this is the sort of thing that might be added to rdf/xml based on the upcoming workshop... 16:02:43 <AndyS> kasei, Graham Klyne would be a good person to ask - he tracks IETF and W3C. 16:02:50 <kasei> if we go ahead with this saddle:resultFormat stuff in the SDs, I'd like to be able to point to URIs for the standard formats. 16:03:06 <SteveH> kasei, didn't saddle: use mime types? 16:03:31 <kasei> it used both mime types and a link to the spec's webpage. 16:03:37 <SteveH> right 16:03:47 <SteveH> given that conneg works on mime types, that's not a bad idea 16:03:53 <kasei> which is fine if you don't have a proper URI, I suppose, but I think we can/should do better. 16:05:19 <kasei> also, with the confusion around some mime types for rdf, I'd rather not lean too heavily on them as identifiers. 16:05:47 <SteveH> true 16:06:23 <Zakim> -AlexPassant 16:06:23 <kasei> especially n-triples. text/plain isn't exactly the most useful thing for conneg. 16:06:24 <Zakim> SW_(SPARQL)10:00AM has ended 16:06:25 <Zakim> Attendees were AndyS, MattPerry, kasei, Ivan, bglimm, +035840564aaaa, tommik, LeeF, AlexPassant, dcharbon2, +0207735aabb, SteveH, AxelPolleres 16:09:21 <AndyS> agree re text/plain. They didn't plan to let it out of the WG as a format - but it escaped. Feral format. 16:09:40 <kasei> heh 16:47:00 <SteveH> SteveH has joined #sparql 17:38:03 <AndyS> AndyS has joined #sparql # SPECIAL MARKER FOR CHATSYNC. DO NOT EDIT THIS LINE OR BELOW. SRCLINESUSED=00000254