IRC log of rdb2rdf on 2010-03-23

Timestamps are in UTC.

16:01:11 [RRSAgent]
RRSAgent has joined #rdb2rdf
16:01:11 [RRSAgent]
logging to
16:01:13 [trackbot]
RRSAgent, make logs world
16:01:13 [Zakim]
Zakim has joined #rdb2rdf
16:01:15 [trackbot]
Zakim, this will be 7322733
16:01:15 [Zakim]
ok, trackbot; I see SW_RDB2RDF()12:00PM scheduled to start now
16:01:16 [trackbot]
Meeting: RDB2RDF Working Group Teleconference
16:01:16 [trackbot]
Date: 23 March 2010
16:01:19 [mhausenblas]
Chair: Ahmed
16:01:23 [mhausenblas]
scribenick: mhausenblas
16:01:28 [mhausenblas]
16:01:32 [mhausenblas]
rrsagent, draft minutes
16:01:32 [RRSAgent]
I have made the request to generate mhausenblas
16:01:35 [mhausenblas]
rrsagent, make record public
16:01:40 [mhausenblas]
Topic: Admin
16:01:42 [MacTed]
Zakim, this is 7322733
16:01:42 [Zakim]
ok, MacTed; that matches SW_RDB2RDF()12:00PM
16:01:46 [Zakim]
16:01:50 [mhausenblas]
regrets+ Harry
16:01:51 [MacTed]
trackbot, start meeting
16:01:51 [trackbot]
Sorry... I don't know anything about this channel
16:01:51 [trackbot]
If you want to associate this channel with an existing Tracker, please say 'trackbot, associate this channel with #channel' (where #channel is the name of default channel for the group)
16:01:55 [MacTed]
16:02:04 [Zakim]
16:02:06 [MacTed]
but it's not done it right
16:02:21 [cygri]
cygri has joined #rdb2rdf
16:02:29 [Zakim]
+ +3539149aacc
16:02:30 [MacTed]
else Zakim would have reported my join
16:02:39 [MacTed]
Zakim, who's here?
16:02:39 [Zakim]
On the phone I see [IPcaller], +1.512.471.aaaa, [IPcaller.a], ??P13, +49.322.222.0.aabb, OpenLink_Software, Ashok_Malhotra, whalb, +3539149aacc
16:02:39 [mhausenblas]
Zakim, cygri is with mhausenblas
16:02:42 [Zakim]
On IRC I see cygri, Zakim, RRSAgent, whalb, Ashok, Ahmed, Marcelo, mhausenblas, MacTed, LeeF, nunolopes, iv_an_ru, trackbot, ericP
16:02:44 [Zakim]
sorry, mhausenblas, I do not recognize a party named 'mhausenblas'
16:02:51 [MacTed]
Zakim, OpenLink_Software is temporarily me
16:02:51 [Zakim]
+MacTed; got it
16:02:53 [MacTed]
Zakim, mute me
16:02:53 [Zakim]
MacTed should now be muted
16:03:04 [Zakim]
16:03:07 [juansequeda]
juansequeda has joined #RDB2RDF
16:03:08 [mhausenblas]
Zakim, aacc is me
16:03:08 [Zakim]
+mhausenblas; got it
16:03:12 [mhausenblas]
Zakim, cygri is with mhausenblas
16:03:12 [Zakim]
+cygri; got it
16:03:17 [ericP]
Zakim, MIT262 as LeeF, ericP
16:03:17 [Zakim]
I don't understand 'MIT262 as LeeF, ericP', ericP
16:03:23 [mhausenblas]
Zakim, nunolopes is with mhausenblas
16:03:23 [Zakim]
+nunolopes; got it
16:03:26 [LeeF]
Zakim, MIT262 has LeeF, EricP
16:03:26 [Zakim]
+LeeF, EricP; got it
16:03:32 [mhausenblas]
RRSAgent, draft minutes
16:03:32 [RRSAgent]
I have made the request to generate mhausenblas
16:03:55 [Zakim]
16:04:22 [Zakim]
16:04:44 [Souri]
Souri has joined #rdb2rdf
16:05:02 [Souri]
zakim, who is on the phone?
16:05:02 [Zakim]
On the phone I see [IPcaller], +1.512.471.aaaa, [IPcaller.a], ??P13, +49.322.222.0.aabb, MacTed (muted), Ashok_Malhotra, whalb, mhausenblas, MIT262, Souri, Seema
16:05:06 [Zakim]
MIT262 has LeeF, EricP
16:05:08 [Zakim]
mhausenblas has mhausenblas, cygri, nunolopes
16:05:18 [Ahmed]
Are we ready to start?
16:05:46 [Seema]
Seema has joined #rdb2rdf
16:06:37 [ericP]
harry will not be here today
16:07:17 [LeeF]
zakim, who is speaking?
16:07:19 [MacTed]
Zakim, who's noisy?
16:07:28 [Zakim]
LeeF, listening for 10 seconds I could not identify any sounds
16:07:33 [LeeF]
zakim, listen harder
16:07:33 [Zakim]
I don't understand 'listen harder', LeeF
16:07:39 [Zakim]
MacTed, listening for 10 seconds I heard sound from the following: +49.322.222.0.aabb (80%), ??P13 (40%), mhausenblas (49%)
16:07:46 [Souri]
Anyone has the URL for the public-rdb2rdf-wg email archive?
16:08:02 [mhausenblas]
Zakim, aabb is Soeren
16:08:02 [Zakim]
+Soeren; got it
16:08:03 [LeeF]
16:08:16 [mhausenblas]
PROPOSAL: accept minutes of previous telecon
16:08:27 [soeren]
soeren has joined #RDB2RDF
16:08:38 [whalb]
16:08:41 [mhausenblas]
RESOLUTION: group accepted minutes of previous telecon
16:09:24 [mhausenblas]
Ahmed: seems like the discussion on the mailing list seems rather minimal
16:09:44 [mhausenblas]
... we need to discuss the idea of the two-team approach
16:10:02 [LeeF]
q+ to ask a beginner's question
16:10:25 [Zakim]
16:11:16 [Souri]
We have sent an email with links to extended version of our example with a Part 3 that has SPARQL Query and its SQL translation (using the SQLdefString).
16:11:19 [Souri]
16:11:40 [mhausenblas]
ack LeeF
16:11:40 [Zakim]
LeeF, you wanted to ask a beginner's question
16:12:27 [mhausenblas]
LeeF: do you view the two approaches as mapping language approaches or implementation specific?
16:12:39 [mhausenblas]
Orri: IMO a matter of syntax
16:12:56 [mhausenblas]
... primarily, yes, as of the preferences of the people
16:13:14 [mhausenblas]
LeeF: that was my understanding as well
16:13:28 [mhausenblas]
... but got confused when I reviewed the WG's material
16:14:08 [juansequeda]
I think it is Souri
16:14:14 [Seema]
it is Souri
16:14:20 [mhausenblas]
thanks ;)
16:14:46 [mhausenblas]
Souri: its about the schema, we need some glue to express it
16:15:29 [mhausenblas]
... view definition should be rather simple
16:16:21 [mhausenblas]
Ahmed: Souri, the mapping the query is an orthogonal issue - we're about mapping data
16:16:46 [LeeF]
Souri, the approach you explained sounds very similar to the D2RQ approach, where the "glue" is given via RDF but the ultimate expressivity is given by SQL fragments... i guess the difference is the SQL approach starts with a full-on SQL query/view?
16:17:10 [mhausenblas]
Souri: we look into mapping a SPARQL to SQL query, re implementation
16:17:32 [mhausenblas]
RRSAgent, draft minutes
16:17:32 [RRSAgent]
I have made the request to generate mhausenblas
16:18:28 [mhausenblas]
Topic: Update from both SQL & RDF mapping approach teams
16:18:41 [soeren]
16:20:01 [mhausenblas]
Orri: Virtuoso is somewhere in the middle of the two approaches
16:20:41 [mhausenblas]
... experience shows that a SPARQL2SQL mapping is essential similar to D2R approach
16:20:55 [LeeF]
My target audience is definitely _not_ SQL people.
16:21:15 [mhausenblas]
Orri: the SQL syntax is easier to sell (taking the target audience into consideration)
16:21:47 [mhausenblas]
... use cases will make the requirements apparent
16:22:23 [cygri]
+1 to everything Souri and Orri said
16:22:58 [mhausenblas]
Ahmed: can be done either way (put load on user or database)
16:23:57 [mhausenblas]
ack soeren
16:24:12 [mhausenblas]
soeren: I think the difference between both approaches is not that big
16:24:42 [mhausenblas]
... in SQL-based approach the view creation is part up-front
16:25:24 [mhausenblas]
... if it can be done in SQL, why redo it?
16:25:37 [mhausenblas]
RRSAgent, draft minutes
16:25:37 [RRSAgent]
I have made the request to generate mhausenblas
16:26:17 [mhausenblas]
Ahmed: agree with Soeren - but you don't need to create a view
16:26:30 [Souri]
16:26:53 [mhausenblas]
ack Souri
16:27:09 [mhausenblas]
Souri: we are *not* creating a view
16:27:15 [Ashok]
16:27:44 [mhausenblas]
ack Ashok
16:28:16 [mhausenblas]
Ashok: want to point out that we're a chartered to write a mapping language
16:28:53 [ericP]
16:28:56 [mhausenblas]
... sure we need to have a ML implemented but not SPARQL2SQL
16:29:00 [Souri]
16:29:10 [LeeF]
The charter gives 2 overall use cases for this group's work:
16:29:15 [LeeF]
1) Dumping RDB data into a triple store
16:29:18 [LeeF]
2) SPARQL to SQL translation
16:29:32 [LeeF]
so it seems a little weird to ignore the 2nd overall use case
16:29:37 [mhausenblas]
soeren: you need a SPARQL2SQL which yields the same
16:30:06 [mhausenblas]
Ahmed: let's step back - JDBC as an example; all about decoupling
16:30:22 [mhausenblas]
ack ericP
16:30:46 [mhausenblas]
ericP: from the spec POV it's nice to say: here is how our mapping works
16:31:02 [mhausenblas]
... but from the uptake , it needs to be implementable
16:31:34 [mhausenblas]
... then, performance becomes very relevant
16:32:16 [Ashok]
Lee, where did you see "2) SPARQL to SQL translation" ?
16:32:25 [mhausenblas]
ericP: Richard, can you confirm that for D2RQ can map always 1:1 in terms of queries?
16:32:27 [Ashok]
It is not in the scope bullets
16:33:06 [mhausenblas]
cygri: AFAICT, it should be possible to always translate 1:1
16:33:37 [mhausenblas]
ericP: do you think the underlying algebra (re D2R) exists?
16:34:00 [mhausenblas]
cygri: for this you need a formal representation for the ML (but this does not exist for D2R)
16:34:43 [mhausenblas]
... if you want to be sure that everything translates 1:1 we'd need it
16:34:55 [mhausenblas]
... would be great to have
16:35:25 [mhausenblas]
ericP: I think we will not have real adoption if we lack this formal semantics
16:35:39 [LeeF]
16:36:01 [mhausenblas]
Orri: Virtuoso uses proprietary extensions in some cases
16:36:39 [LeeF]
I don't think the question is "can it be done" - the question is, how can I know when I've efficiently handled all cases
16:36:55 [Zakim]
16:37:03 [mhausenblas]
Souri: the aspect 'is it translateable' is not in scope (could be in a certain form)
16:37:11 [mhausenblas]
ack Souri
16:37:11 [juansequeda]
16:38:09 [mhausenblas]
Souri: proofing that a SPARQL query can be translated into x SQL queries, is out of scope
16:38:35 [mhausenblas]
ack juansequeda
16:39:21 [mhausenblas]
juansequeda: need the semantics of the mapping language; we just guarantee that it works, not how to implement it
16:39:31 [Souri]
16:39:36 [Souri]
16:39:47 [mhausenblas]
Ahmed: we should ensure that the ML is semantic valid
16:39:54 [mhausenblas]
ack Souri
16:39:59 [mhausenblas]
Souri: I disagree
16:40:13 [mhausenblas]
... we want to expose relational data as RDF
16:40:27 [mhausenblas]
(explains a simple example)
16:42:37 [mhausenblas]
Juan: we need both syntax and semantics, so we know what the language means
16:42:55 [Marcelo]
I agree with Juan
16:43:02 [Souri]
16:43:49 [mhausenblas]
Souri: with SQL approach, we use the SQL semantics which is well-known ... the semantics of the glue is very simple
16:44:28 [ericP]
16:44:32 [ericP]
16:44:45 [mhausenblas]
soeren: how to be sure that a SPARQL query over your mapping into a SQL query is always possible?
16:45:02 [mhausenblas]
Soeren: that's independent from the mapping, not part of charter of this group
16:45:12 [mhausenblas]
s/Soeren/Souri/ in above
16:45:38 [MacTed]
Zakim, unmute me
16:45:38 [Zakim]
MacTed should no longer be muted
16:45:42 [MacTed]
16:45:53 [mhausenblas]
ack Souri
16:46:10 [MacTed]
can you guarantee that any SQL query can be executed?
16:46:19 [mhausenblas]
RRSAgent, draft minutes
16:46:19 [RRSAgent]
I have made the request to generate mhausenblas
16:46:19 [MacTed]
especially, within reasonable time?
16:46:29 [Ashok]
16:48:37 [Ashok]
16:49:45 [mhausenblas]
(Ahmed and Souri discuss SQL details)
16:50:03 [mhausenblas]
16:50:29 [mhausenblas]
ack ericP
16:51:01 [mhausenblas]
ericP: we have a rough equivalence between SPARQL and SQL, beside the fact that the latter is much more epxressive
16:51:25 [mhausenblas]
... for example SQL views
16:51:56 [mhausenblas]
... if I use a trivial representation of relational data as, say XML
16:52:26 [mhausenblas]
(ericP has lost the scribe and will fill in the missing bits of his interesting example after the meeting)
16:53:18 [mhausenblas]
Souri: what is the mapping language, really?
16:53:51 [mhausenblas]
16:53:59 [cygri]
q+ to agree with Souri
16:55:27 [mhausenblas]
juansequeda: 1:1 is simple, do we have 1:many use cases?
16:56:28 [mhausenblas]
MacTed: does it make sense to give such a query-mapping gurantee?
16:57:18 [mhausenblas]
soeren: every valid SQL is; we should at least define which ones are guaranteed to be mapped
16:57:56 [cygri]
16:57:58 [mhausenblas]
MacTed: not saying it is efficient - might take forever
16:58:44 [MacTed]
ack MacTed
16:58:53 [Zakim]
16:58:57 [MacTed]
Zakim, mute me
16:58:57 [Zakim]
MacTed should now be muted
16:59:02 [soeren_]
soeren_ has joined #RDB2RDF
17:00:36 [mhausenblas]
ericP: I ended up owning the UC doc
17:00:56 [cygri]
soeren has already dropped from the call
17:01:09 [mhausenblas]
ACTION: ericP to review the UC and report back to the WG
17:01:09 [trackbot]
Sorry, couldn't find user - ericP
17:01:51 [LeeF]
ACTION: eric to review the UC and report back to the WG with requests for more details
17:01:51 [trackbot]
Created ACTION-36 - Review the UC and report back to the WG with requests for more details [on Eric Prud'hommeaux - due 2010-03-30].
17:03:40 [MacTed]
Zakim, unmute me
17:03:40 [Zakim]
MacTed should no longer be muted
17:04:20 [MacTed]
Zakim, mute me
17:04:20 [Zakim]
MacTed should now be muted
17:04:26 [mhausenblas]
ACTION: Orri to sum up today's discussion
17:04:26 [trackbot]
Created ACTION-37 - Sum up today's discussion [on Orri Erling - due 2010-03-30].
17:04:43 [Zakim]
17:04:45 [Zakim]
17:04:45 [Zakim]
17:04:47 [Zakim]
17:04:47 [Zakim]
17:04:48 [mhausenblas]
17:04:49 [Zakim]
17:04:51 [Zakim]
17:04:53 [Zakim]
17:04:54 [mhausenblas]
zakim, list attendees
17:04:55 [Zakim]
- +1.512.471.aaaa
17:04:57 [Zakim]
As of this point the attendees have been [IPcaller], +1.512.471.aaaa, +49.322.222.0.aabb, Ashok_Malhotra, whalb, +3539149aacc, MacTed, mhausenblas, cygri, nunolopes, LeeF, EricP,
17:04:59 [Zakim]
... Souri, Seema, Soeren
17:04:59 [Zakim]
17:05:02 [Zakim]
17:05:04 [Zakim]
SW_RDB2RDF()12:00PM has ended
17:05:04 [mhausenblas]
rrsagent, draft minutes
17:05:04 [RRSAgent]
I have made the request to generate mhausenblas
17:05:04 [juansequeda]
LeeF, you still there?\
17:05:07 [Zakim]
Attendees were [IPcaller], +1.512.471.aaaa, +49.322.222.0.aabb, Ashok_Malhotra, whalb, +3539149aacc, MacTed, mhausenblas, cygri, nunolopes, LeeF, EricP, Souri, Seema, Soeren
17:11:49 [mhausenblas]
bye Zakim
17:11:55 [mhausenblas]
bye RRSAgent
17:12:00 [mhausenblas]
Zakim, bye
17:12:00 [Zakim]
Zakim has left #rdb2rdf
17:12:05 [mhausenblas]
RRSAgent, bye
17:12:05 [RRSAgent]
I see 3 open action items saved in :
17:12:05 [RRSAgent]
ACTION: ericP to review the UC and report back to the WG [1]
17:12:05 [RRSAgent]
recorded in
17:12:05 [RRSAgent]
ACTION: eric to review the UC and report back to the WG with requests for more details [2]
17:12:05 [RRSAgent]
recorded in
17:12:05 [RRSAgent]
ACTION: Orri to sum up today's discussion [3]
17:12:05 [RRSAgent]
recorded in