IRC log of rdb2rdf on 2011-05-31

Timestamps are in UTC.

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
18:28:50 [betehess]
betehess has joined #RDB2RDF
19:32:16 [Zakim]
Zakim has left #rdb2rdf