15:58:53 <RRSAgent> RRSAgent has joined #rdb2rdf
15:58:53 <RRSAgent> logging to http://www.w3.org/2011/05/31-rdb2rdf-irc
15:58:55 <trackbot> RRSAgent, make logs world
15:58:55 <Zakim> Zakim has joined #rdb2rdf
15:58:57 <trackbot> Zakim, this will be 7322733
15:58:57 <Zakim> ok, trackbot; I see SW_RDB2RDF()12:00PM scheduled to start in 2 minutes
15:58:58 <trackbot> Meeting: RDB2RDF Working Group Teleconference
15:58:58 <trackbot> Date: 31 May 2011
15:59:51 <soeren> soeren has joined #RDB2RDF
16:00:45 <Zakim> SW_RDB2RDF()12:00PM has now started
16:00:53 <Zakim> + +90700156aaaa
16:01:08 <soeren> zakim, aaaa is soeren
16:01:08 <Zakim> +soeren; got it
16:01:42 <dmcneil> dmcneil has joined #RDB2RDF
16:01:49 <Zakim> +Ashok_Malhotra
16:02:30 <Zakim> +juansequeda
16:02:43 <juansequeda> juansequeda has joined #rdb2rdf
16:03:15 <Zakim> +Alexandre
16:03:27 <Zakim> +dmcneil
16:04:41 <Ashok> zakim, pick a victim
16:04:41 <Zakim> Not knowing who is chairing or who scribed recently, I propose soeren
16:05:03 <ivan> zakim, dial ivan-voip
16:05:03 <Zakim> ok, ivan; the call is being made
16:05:04 <Zakim> +Ivan
16:05:09 <Zakim> +Souri
16:05:18 <Ashok> Topic: Approval of Minutes
16:05:44 <soeren> http://www.w3.org/2011/05/24-rdb2rdf-minutes.html
16:06:25 <Souri> Souri has joined #rdb2rdf
16:06:44 <soeren> resolution: minutes from 2011/5/24 approved
16:06:49 <Seema> Seema has joined #rdb2rdf
16:06:59 <soeren> Topic: ISSUE 42
16:07:08 <soeren> http://www.w3.org/2001/sw/rdb2rdf/wiki/RDBNullValues
16:07:09 <ivan> issue-42?
16:07:09 <trackbot> ISSUE-42 -- How is the direct mapping suppose to handle NULL values wrt Information Preserving -- open
16:07:09 <trackbot> http://www.w3.org/2001/sw/rdb2rdf/track/issues/42
16:07:32 <Zakim> +Seema
16:07:34 <Ashok> Regrets:  Percy, Marcelo
16:07:53 <Zakim> -soeren
16:08:20 <juansequeda> <Souri> My proposal: maintain data equivalence (allowing converting either way, without loss of info) => this can be done by DM 1) always generating schema triples and 2) skipping generation of triples for NULL values
16:08:49 <Zakim> +??P5
16:08:50 <dmcneil> +1
16:08:54 <betehess> +1
16:09:02 <soeren> zakim, ??P5 is soeren
16:09:02 <Zakim> +soeren; got it
16:09:32 <dmcneil> +q
16:09:32 <ivan> q+
16:09:51 <Zakim> +EricP
16:10:18 <soeren> david: acceptable but it should be proved that this is valid
16:10:37 <soeren> ashok: what does proving mean?
16:11:32 <Ashok> s/david/enrico
16:12:12 <dmcneil> -q
16:12:17 <soeren> david: for other parts of the mapping also no proofs were made
16:12:41 <soeren> ivan: procedural problem - the main persons are not on the call
16:12:45 <Souri> Richard and Enrico?
16:13:30 <Souri> +1 to sending emails to both to confirm
16:13:34 <soeren> action: send email to richard and enrico about finding a compromise and closing the issue
16:13:34 <trackbot> Sorry, couldn't find user - send
16:13:49 <Zakim> +juansequeda.a
16:13:55 <Zakim> -juansequeda
16:13:58 <betehess> q+
16:14:10 <soeren> david: should correctness be proved?
16:14:26 <betehess> q+ to comment on the proof
16:14:36 <Souri> q+
16:14:40 <ivan> q-
16:16:05 <Ashok> q?
16:16:11 <soeren> alexander: proofs are not required
16:16:38 <Ashok> s/alexander/Eric/
16:16:43 <juansequeda> q+
16:16:51 <soeren> intuitive query in sparql should give the same results as in SQL
16:17:21 <betehess> guys, please read this email I sent a while ago http://www.w3.org/mid/1287693123.21135.419.camel@simplet
16:17:36 <ivan> zakim, who is noisy?
16:17:46 <Zakim> ivan, listening for 10 seconds I heard sound from the following: juansequeda.a (59%), Alexandre (100%)
16:18:03 <soeren> Alexandre: proof is difficult
16:18:52 <soeren> Alexandre: proof is a lot of work but could be done
16:19:11 <soeren> Alexandre: reverse mapping is the only interesting thing
16:19:30 <soeren> Alexandre: we should be confident that the reverse way is possible
16:19:42 <soeren> Alexandre: implementations will provide a proof-of-concept
16:20:03 <soeren> Eric: proof do not say much about the usability
16:20:32 <betehess> [[
16:20:33 <betehess> Theorem:
16:20:33 <betehess> ∀ rdb-dataset ∈ RDB, ∀ sparql-query ∈ SPARQL,
16:20:33 <betehess> (SPARQL2SQL(sparql-query))(rdb-dataset) =
16:20:33 <betehess> sparql-query(RDB2RDF(rdb-dataset))
16:20:34 <betehess> ]]
16:20:56 <soeren> souri: information should not be lost
16:21:18 <soeren> souri: formal proof is nice-to-have but no requirement
16:21:22 <betehess> Or in plain English:
16:21:22 <betehess> [[
16:21:22 <betehess> Given a SPARQL-to-SQL mapping to access an RDB dataset, the semantics of
16:21:22 <betehess> the translated SPARQL query executed against this particular RDB dataset
16:21:23 <betehess> should be equivalent to the same SPARQL query executed against the same
16:21:25 <betehess> RDB dataset seen through the RDB2RDF mapping.
16:21:27 <betehess> ]]
16:21:30 <Ashok> q?
16:21:33 <betehess> q-
16:21:33 <soeren> ashok: reversability is the proof
16:21:41 <Ashok> ack next
16:22:00 <Ashok> ack next
16:22:11 <juansequeda> T(Q(I)) = Q*(DirectMapping(I, S))
16:22:12 <soeren> juan: paper about the proof is in the works for ISWC
16:22:19 <Souri> q?
16:22:51 <juansequeda> F(DirectMapping(I, S)) = I
16:23:29 <soeren> juan: information preserving is important and proved in the paper
16:24:04 <soeren> topic: issue-22
16:24:10 <ivan> issue-22?
16:24:10 <trackbot> ISSUE-22 -- Support for database vendor specific SQL statements. -- open
16:24:10 <trackbot> http://www.w3.org/2001/sw/rdb2rdf/track/issues/22
16:25:09 <soeren> richard sent a proposal by email
16:25:44 <soeren> david: SQL queries should be SQL2008 compliant
16:26:15 <soeren> david: for validation purposes projecttions should be kept track of
16:26:53 <soeren> david: SQL queries can be created as a resource
16:27:17 <soeren> david: in addition to the text of the query it can be annotated to be vendor specific
16:28:40 <dmcneil> +q
16:28:55 <betehess> can't we just allow people to use another RDF type than xsd:string?
16:29:01 <soeren> eric: SQL2008 is not so important, but the provenance and compliance of the query should be preserved
16:29:54 <soeren> eric: there should be a property to indicate the compliance of the query (default SQL2008)
16:30:35 <dmcneil> -q
16:30:37 <soeren> eric: value of the property should be URIs
16:30:51 <soeren> ... not literals/strings
16:32:49 <soeren> Souri: introducing URIs opens up questions about authority
16:33:12 <soeren> Eric: creation of URIs should not be an obstacle
16:33:27 <dmcneil> betehess - what data type do you have in mind?
16:34:12 <soeren> Souri: creation of URIs might be difficult due to the vast number of product variations
16:34:56 <soeren> Ashok: group seems to agree that a property is required to annotate the queries
16:34:58 <betehess> dmcneil, assuming it's an URI, I was wondering if writing "SELECT ..."^^sql-vendor-uri makes sense, but I don't know...
16:35:15 <dmcneil> i see
16:35:31 <soeren> Ashok: questions: 1) is it a string or a URI, 2) what values should be used
16:35:47 <dmcneil> +q
16:36:35 <ericP> q?
16:36:39 <soeren> souri, there should be more complex data structure representing the specific product
16:37:52 <soeren> souri: are we standardizing the product types - probably not - should be done by the users
16:38:47 <ericP> q+ to say that, given certain identifiers there, they may still be able to optimize
16:38:48 <soeren> david: sql2008 queries can be used and optimized, other queries are opaque
16:39:34 <soeren> ashok: issue should again be discussed in the next week and resolved later
16:40:17 <soeren> action: eric to write proposal for issue-22
16:40:17 <trackbot> Created ACTION-133 - Write proposal for issue-22 [on Eric Prud'hommeaux - due 2011-06-07].
16:40:54 <dmcneil> -q
16:41:11 <soeren> topic: issue-18
16:41:19 <soeren> issue-18?
16:41:19 <trackbot> Sorry... I don't know anything about this channel
16:41:41 <soeren> action-126?
16:41:41 <trackbot> Sorry... I don't know anything about this channel
16:41:59 <soeren> http://www.w3.org/2001/sw/rdb2rdf/track/issues/18
16:42:33 <soeren> souri: make sure that all class and property names are meaningful
16:42:56 <soeren> ... document is modified
16:43:07 <soeren> ... renaming should be discussed
16:43:15 <ericP> +1 to reviewing the name change now
16:43:37 <ericP> topic: renaming R2RML class names
16:43:43 <Souri> class names *MapClass ==> *Map
16:43:50 <ericP> +1
16:43:50 <Ashok> regrets+: Enrico, Michael
16:44:10 <soeren> +1
16:44:22 <Souri> property names *Map ==> use*Map
16:44:40 <Souri> example: rr:subjectMap  ==> rr:useSubjectMap
16:45:05 <dmcneil> personally, I preferred the old naming scheme (sorry :( )
16:45:17 <ericP> i have no issue with _:someTriplesMap rr:subjectMap [ a rr:SubjectMap ... ]
16:45:43 <betehess> +1
16:46:07 <soeren> Eric, mixed approach or "with" instead of "use"
16:46:27 <Souri> ericP:  rr:useSubjectMap   ==>  rr:withSubjectMap
16:46:41 <soeren> ivan: if capitalization is the only difference makes it quite easy to make mistakes
16:46:45 <Seema> prefer different names for class and property
16:46:46 <ericP> q+ to ask if class labels are necessary
16:47:09 <Ashok> zakim, who is on the phone?
16:47:09 <Zakim> On the phone I see Ashok_Malhotra, Alexandre, dmcneil, Ivan, Souri, Seema, soeren, EricP, juansequeda.a
16:47:32 <soeren> david: property names should be kept brief, since used more frequently
16:48:37 <soeren> ivan: when R2RML file is written, type declarations can be ommited
16:49:12 <soeren> souri: "use" is only three letters
16:49:40 <soeren> eric: what's the most intuitive for the user to write?
16:49:54 <Souri> use => verb: seems nice for predicate
16:50:25 <soeren> Eric: intuitive predicate names are more important than intuitive class names
16:50:59 <soeren> souri: happy to get rid of "class" suffix
16:52:42 <soeren> souri: class names are important from a pedagogic point of view
16:53:10 <ericP> topic: SQL Query Reuse (Issue 18)
16:53:33 <soeren> ashok: wasn't there already agreement on issue-18?
16:55:39 <dmcneil> will there be an opportunity for an informal working group get-together at semtech next week?
16:56:23 <soeren> topic: issue-25
16:56:33 <soeren> issue-25?
16:56:33 <trackbot> Sorry... I don't know anything about this channel
16:56:34 <ericP> dmcneil, i'll be at semtech
16:56:44 <ericP> (and anxious to meet up)
16:56:49 <betehess> q+
16:57:02 <ericP> (sorry i didn't geek with your crew at enterprise data world)
16:57:07 <soeren> ashok: why is issue-25 still open?
16:57:19 <betehess> issue-25?
16:57:19 <trackbot> Sorry... I don't know anything about this channel
16:57:24 <soeren> souri: still have an action on that
16:57:29 <betehess> q-
16:57:34 <soeren> topic: semtec meeting
16:57:35 <Seema> me too
16:58:05 <Ashok> rrsagent, make logs public
16:58:53 <Zakim> -Ivan
16:58:55 <ericP> Zakim, who is speaking?
16:59:06 <Zakim> ericP, listening for 10 seconds I heard sound from the following: juansequeda.a (15%), Ashok_Malhotra (69%)
16:59:37 <juansequeda> +1 to shout together
16:59:52 <cygri> cygri has joined #rdb2rdf
16:59:58 <soeren> ashok: telco will still take place next week
17:00:25 <Zakim> -Souri
17:00:29 <Zakim> -Seema
17:00:47 <Ashok> rrsagent, make minutes
17:00:47 <RRSAgent> I have made the request to generate http://www.w3.org/2011/05/31-rdb2rdf-minutes.html Ashok
17:01:58 <Zakim> -soeren
17:02:05 <Ashok> present: Ashok_Malhotra, Alexandre, dmcneil, Ivan, Souri, Seema, soeren, EricP, juansequeda
17:02:13 <Zakim> -juansequeda.a
17:02:19 <Ashok> rrsagent, make minutes
17:02:19 <RRSAgent> I have made the request to generate http://www.w3.org/2011/05/31-rdb2rdf-minutes.html Ashok
17:06:36 <betehess> Zakim, who is on the phone?
17:06:36 <Zakim> On the phone I see Ashok_Malhotra, Alexandre, dmcneil, EricP
17:14:35 <Zakim> -Ashok_Malhotra
17:18:46 <Zakim> -EricP
17:18:47 <Zakim> -dmcneil
17:18:47 <Zakim> -Alexandre
17:18:49 <Zakim> SW_RDB2RDF()12:00PM has ended
17:18:51 <Zakim> Attendees were +90700156aaaa, soeren, Ashok_Malhotra, juansequeda, Alexandre, dmcneil, Ivan, Souri, Seema, EricP
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