IRC log of RDB2RDF on 2010-02-02

Timestamps are in UTC.

17:00:49 [RRSAgent]
RRSAgent has joined #RDB2RDF
17:00:49 [RRSAgent]
logging to http://www.w3.org/2010/02/02-RDB2RDF-irc
17:00:51 [trackbot]
RRSAgent, make logs world
17:00:51 [Zakim]
Zakim has joined #RDB2RDF
17:00:53 [trackbot]
Zakim, this will be 7322733
17:00:53 [Zakim]
ok, trackbot; I see SW_RDB2RDF()12:00PM scheduled to start now
17:00:54 [trackbot]
Meeting: RDB2RDF Working Group Teleconference
17:00:54 [trackbot]
Date: 02 February 2010
17:00:57 [mhausenblas]
Chair: Ahmed
17:01:02 [mhausenblas]
Agenda: http://lists.w3.org/Archives/Public/public-rdb2rdf-wg/2010Feb/0000.html
17:01:07 [mhausenblas]
Scribenick: mhausenblas
17:01:11 [mhausenblas]
Topic: Admin
17:01:12 [angela_UNITN]
angela_UNITN has joined #RDB2RDF
17:01:19 [MacTed]
Zakim, who's here?
17:01:19 [Zakim]
SW_RDB2RDF()12:00PM has not yet started, MacTed
17:01:20 [Zakim]
On IRC I see angela_UNITN, Zakim, RRSAgent, juansequeda, Ahmed, Seema, Ashok, BenSzekely, mdean, nunolopes, MacTed, mhausenblas, iv_an_ru, trackbot, ericP
17:01:27 [MacTed]
Zakim, this is 7322733
17:01:29 [Zakim]
ok, MacTed; that matches SW_RDB2RDF()12:00PM
17:01:31 [MacTed]
Zakim, who's here?
17:01:35 [Zakim]
On the phone I see ??P4, hhalpin, OpenLink_Software
17:01:41 [Zakim]
On IRC I see angela_UNITN, Zakim, RRSAgent, juansequeda, Ahmed, Seema, Ashok, BenSzekely, mdean, nunolopes, MacTed, mhausenblas, iv_an_ru, trackbot, ericP
17:01:44 [MacTed]
Zakim, OpenLink_Software is temporarily me
17:01:46 [Zakim]
+ +1.617.306.aaaa
17:01:47 [MacTed]
Zakim, mute me
17:01:50 [Zakim]
+mhausenblas
17:01:50 [ericP]
Zakim, please dial ericp-office
17:01:52 [Zakim]
+MacTed; got it
17:01:56 [Zakim]
MacTed should now be muted
17:02:00 [Zakim]
ok, ericP; the call is being made
17:02:00 [cygri]
cygri has joined #rdb2rdf
17:02:06 [Zakim]
+Ericp
17:02:23 [Zakim]
+Ashok_Malhotra
17:02:25 [mhausenblas]
regrets+ Marcelo
17:02:36 [mhausenblas]
regrets+ Li Ma
17:02:48 [mhausenblas]
regrets+ Harry
17:02:49 [Zakim]
+ +1.512.471.aabb
17:02:56 [soeren]
soeren has joined #RDB2RDF
17:03:00 [mhausenblas]
Zakim, aabb is juansequeda
17:03:05 [mhausenblas]
Zakim, who's here?
17:03:07 [Zakim]
+juansequeda; got it
17:03:13 [Zakim]
On the phone I see ??P4, hhalpin, MacTed (muted), +1.617.306.aaaa, mhausenblas, Ericp, Ashok_Malhotra, juansequeda
17:03:14 [mhausenblas]
Zakim, cygri is with mhausenblas
17:03:26 [Zakim]
On IRC I see soeren, cygri, angela_UNITN, Zakim, RRSAgent, juansequeda, Ahmed, Seema, Ashok, BenSzekely, mdean, nunolopes, MacTed, mhausenblas, iv_an_ru, trackbot, ericP
17:03:29 [Zakim]
+cygri; got it
17:03:31 [Zakim]
+ +039046188aacc
17:03:31 [BenSzekely]
+1.617.306.aaaa is me
17:03:37 [Zakim]
+ +49.322.22.aadd
17:03:38 [nunolopes]
Zakim, nunolopes is with mhausenblas
17:03:51 [Zakim]
+nunolopes; got it
17:03:56 [soeren]
zakim, aadd is me
17:04:03 [Zakim]
+soeren; got it
17:04:13 [angela_UNITN]
aacc is me
17:04:19 [mhausenblas]
Zakim, who's here?
17:04:19 [Zakim]
On the phone I see ??P4, hhalpin, MacTed (muted), +1.617.306.aaaa, mhausenblas, Ericp, Ashok_Malhotra, juansequeda, +039046188aacc, soeren
17:04:22 [Zakim]
On IRC I see soeren, cygri, angela_UNITN, Zakim, RRSAgent, juansequeda, Ahmed, Seema, Ashok, BenSzekely, mdean, nunolopes, MacTed, mhausenblas, iv_an_ru, trackbot, ericP
17:04:24 [Zakim]
mhausenblas has mhausenblas, cygri, nunolopes
17:05:44 [mhausenblas]
Ahmed?
17:06:45 [mhausenblas]
Zakim, who's here?
17:06:45 [Zakim]
On the phone I see ??P4, hhalpin, MacTed (muted), +1.617.306.aaaa, mhausenblas, Ericp, Ashok_Malhotra, juansequeda, +039046188aacc, soeren
17:06:47 [Zakim]
On IRC I see soeren, cygri, angela_UNITN, Zakim, RRSAgent, juansequeda, Ahmed, Seema, Ashok, BenSzekely, mdean, nunolopes, MacTed, mhausenblas, iv_an_ru, trackbot, ericP
17:06:50 [Zakim]
mhausenblas has mhausenblas, cygri, nunolopes
17:07:44 [BenSzekely]
*4
17:09:37 [MacTed]
Zakim, who's making noise
17:09:37 [Zakim]
I don't understand 'who's making noise', MacTed
17:09:44 [MacTed]
Zakim, who's making noise?
17:09:55 [Zakim]
MacTed, listening for 10 seconds I heard sound from the following: ??P4 (37%), +039046188aacc (20%), +1.617.306.aaaa (85%)
17:11:00 [mhausenblas]
PROPOSAL: accept minutes of previous telecon http://www.w3.org/2010/01/26-RDB2RDF-minutes.html
17:11:23 [ericP]
+1
17:11:26 [soeren]
+1
17:11:34 [mhausenblas]
RESOLUTION: accept minutes of previous telecon http://www.w3.org/2010/01/26-RDB2RDF-minutes.html
17:12:37 [juansequeda]
http://www.w3.org/2001/sw/rdb2rdf/wiki/GeneratedSQL
17:12:40 [juansequeda]
http://www.w3.org/2001/sw/rdb2rdf/wiki/PotentialSQLIssues
17:13:03 [ericP]
http://esw.w3.org/topic/HCLSIG/RDB2RDF_Use_Cases
17:15:43 [mhausenblas]
Topic: work planning
17:16:08 [mhausenblas]
ericP: how do we communicate what a mapping does
17:16:24 [mhausenblas]
... here is the input data in relational form and here is the RDF
17:17:01 [mhausenblas]
... so we want to pick a fairly neutral SQL and as an output a Turtle graph
17:17:06 [mhausenblas]
... no NG for now
17:17:51 [mhausenblas]
Ahmed: why not use RDF/XML for the output?
17:17:59 [mhausenblas]
ericP: maybe Turtle is easier
17:18:08 [mhausenblas]
... for manual editing/reviewing
17:18:36 [mhausenblas]
rrsagent, draft minutes
17:18:36 [RRSAgent]
I have made the request to generate http://www.w3.org/2010/02/02-RDB2RDF-minutes.html mhausenblas
17:18:43 [mhausenblas]
rrsagent, make record public
17:19:00 [mhausenblas]
ericP: put the tabular, SQL form into the Wiki
17:19:27 [mhausenblas]
soeren: for what kind of data you mean SQL? for the TC, etc?
17:21:33 [mhausenblas]
q+ to ask about the focus
17:21:50 [mhausenblas]
ack me
17:21:50 [Zakim]
mhausenblas, you wanted to ask about the focus
17:22:00 [ericP]
INSERT INTO People (id, name) VALUES (18, "Bob"), (23, "Sue")
17:23:57 [mhausenblas]
ericP: I'm trying to set up a framework to communicate between our TF and HCLS
17:25:03 [mhausenblas]
soeren: should be called relational-annotation approach
17:26:54 [mhausenblas]
Michael: I see two fundamental approaches - SQL-based mapping and dedicated-language-based mapping
17:27:43 [cygri]
q+
17:27:53 [angela]
angela has joined #RDB2RDF
17:28:45 [mhausenblas]
ack cygri
17:28:58 [juansequeda]
q+
17:29:22 [mhausenblas]
cygri: I'd argue that the relational-annotation approach doesn't work for complex cases without using SQL views
17:30:03 [mhausenblas]
soeren: a more direct approach like ericP's might perform better
17:30:17 [mhausenblas]
... without domain-mappings
17:32:32 [mhausenblas]
cygri: relational-annotation approach will require schema modification IMO
17:33:34 [mhausenblas]
... if one uses relational-annotation the without schema modification, the efficiency is very bad at least on MySQL
17:34:01 [mhausenblas]
... this leads to a big problem
17:34:02 [soeren]
q+
17:34:12 [mhausenblas]
... we hence need to talk about performance as well
17:34:15 [mhausenblas]
queue?
17:35:21 [ericP]
cygri's was talking about recent contributions to http://www.w3.org/2001/sw/rdb2rdf/wiki/PotentialSQLIssues (i believe)
17:35:49 [mhausenblas]
soeren: performance will drop once you want a domain mapping
17:36:31 [mhausenblas]
ack juansequeda
17:36:48 [mhausenblas]
juansequeda: we do need two groups
17:36:57 [mhausenblas]
... question is where the optimisation is done
17:37:29 [mhausenblas]
... in Ultrawrap we change the scheme and let the engine do the rest
17:37:40 [mhausenblas]
queue?
17:37:52 [ericP]
i'm not convinced that the "schema-less" queries need to be pre-optimized any more than if they do it on the SQL side
17:37:54 [soeren]
-q
17:38:03 [Seema]
q+
17:38:44 [mhausenblas]
ack Seema
17:39:13 [mhausenblas]
Seema: so we have two groups? one modify schema and other non-modify schema?
17:39:14 [ericP]
+1 to Seema's characterization
17:39:25 [ericP]
at least, that's how i understand it
17:39:42 [mhausenblas]
cygri: seems that people think along different lines
17:40:05 [mhausenblas]
... schema-modify vs. non, optimising in the mapping vs. not, etc
17:40:27 [mhausenblas]
... personally I think it doesn't matter. we will end up in two groups
17:40:37 [mhausenblas]
RRSAgent, draft minutes
17:40:37 [RRSAgent]
I have made the request to generate http://www.w3.org/2010/02/02-RDB2RDF-minutes.html mhausenblas
17:41:02 [ericP]
i think that the distinction based on the language of the rule body is the least controversion
17:41:17 [ericP]
s/controversion/controversial/
17:41:44 [mhausenblas]
cygri: we should not focus on the question of schema-modify, matter of performance
17:41:58 [mhausenblas]
... rather focus on where the optimisation occurs
17:42:44 [mhausenblas]
juansequeda: R2RML is a mapping language so should be independent where the optimisation is done
17:43:08 [mhausenblas]
cygri: if done with SQL, one would naturally do the optimisation in the RDBMS
17:43:28 [mhausenblas]
... if done outside, better have something which is easy to parse
17:43:29 [Ashok]
Q+
17:43:37 [mhausenblas]
ack Ashok
17:43:40 [ericP]
q+ to characterize one language as an RDF language
17:44:02 [mhausenblas]
Ashok: cygri, why optimisation focus?
17:44:24 [mhausenblas]
... no need to duplicate the work done in the past 30y
17:44:39 [mhausenblas]
cygri: in case of MySQl, for instance this is a problem
17:45:07 [ericP]
q-
17:45:13 [mhausenblas]
Ahmed: we come from the use cases
17:45:35 [mhausenblas]
... there are cases where it is not possible to change the schema
17:45:39 [mhausenblas]
queue?
17:46:40 [mhausenblas]
Ahmed: any mapping language we come up with needs to support all use cases
17:47:32 [mhausenblas]
Ashok: my question is simply - why are we speaking about changing the schema?
17:47:41 [mhausenblas]
Ahmed: because of the views
17:48:04 [mhausenblas]
Ashok: so you're talking about creating views. IMO this is not changing the schema
17:48:18 [mhausenblas]
Ahmed: well, maybe read-only, but still a change
17:48:39 [mhausenblas]
Ahmed: we have such scenarios in-house
17:48:52 [mhausenblas]
RRSAgent, draft minutes
17:48:52 [RRSAgent]
I have made the request to generate http://www.w3.org/2010/02/02-RDB2RDF-minutes.html mhausenblas
17:49:11 [mhausenblas]
Ashok: but the views don't need to be stored, just executed, right?
17:49:16 [mhausenblas]
Ahmed: correct
17:49:40 [mhausenblas]
... but some engines, such as MySQL have issues with it
17:49:48 [mhausenblas]
queue
17:49:51 [mhausenblas]
queue?
17:50:08 [mhausenblas]
cygri: agree, that was a nice summary
17:50:21 [mhausenblas]
cygri: re issues, see http://www.w3.org/2001/sw/rdb2rdf/wiki/PotentialSQLIssues
17:50:37 [mhausenblas]
... has examples in there where we have problems
17:50:59 [mhausenblas]
Ahmed: if MySQL is limited re this, we might need another approach
17:51:02 [ericP]
q?
17:52:02 [mhausenblas]
juansequeda: SQLServer has no problem with it
17:52:56 [mhausenblas]
cygri: at least for D2RQ it is true that MySQL is very often used
17:53:11 [mhausenblas]
... so needs to work with it reasonable well
17:53:51 [mhausenblas]
cygri: as long as I can rewrite the query myself to deal with the specific weaknesses of the target
17:54:01 [mhausenblas]
... I guess it's doable
17:54:12 [ericP]
cygri, wouldn't it be easier in the long run to fix the database's optimizer? (half joking)
17:54:27 [mhausenblas]
cygri: but shouldn't show up in the mapping lanuage
17:54:52 [mhausenblas]
... in D2RQ the mapping is broken down onto class/prop level
17:54:57 [juansequeda]
ericP: we told our students to implement merge join for mysql
17:55:25 [ericP]
cool, nice to see open source improvements
17:56:15 [juansequeda]
oops, i meant coma
17:56:32 [mhausenblas]
s/ericP: we /ericP, we
17:56:38 [mhausenblas]
RRSAgent, draft minutes
17:56:38 [RRSAgent]
I have made the request to generate http://www.w3.org/2010/02/02-RDB2RDF-minutes.html mhausenblas
17:57:00 [mhausenblas]
Ahmed: gotta go soon
17:57:17 [mhausenblas]
... continue next week
17:57:55 [mhausenblas]
[adjourned]
17:57:57 [Zakim]
-??P4
17:57:59 [Zakim]
-hhalpin
17:58:00 [Zakim]
-mhausenblas
17:58:02 [Zakim]
-Ashok_Malhotra
17:58:02 [Zakim]
-soeren
17:58:03 [Zakim]
-MacTed
17:58:04 [mhausenblas]
zakim, list attendees
17:58:05 [Zakim]
As of this point the attendees have been hhalpin, +1.617.306.aaaa, mhausenblas, MacTed, Ericp, Ashok_Malhotra, +1.512.471.aabb, juansequeda, cygri, +039046188aacc, +49.322.22.aadd,
17:58:07 [Zakim]
-juansequeda
17:58:07 [Zakim]
... nunolopes, soeren
17:58:09 [Zakim]
- +1.617.306.aaaa
17:58:16 [mhausenblas]
rrsagent, draft minutes
17:58:16 [RRSAgent]
I have made the request to generate http://www.w3.org/2010/02/02-RDB2RDF-minutes.html mhausenblas
17:58:18 [Zakim]
- +039046188aacc
17:58:51 [mhausenblas]
zakim, bye
17:58:51 [Zakim]
leaving. As of this point the attendees were hhalpin, +1.617.306.aaaa, mhausenblas, MacTed, Ericp, Ashok_Malhotra, +1.512.471.aabb, juansequeda, cygri, +039046188aacc,
17:58:51 [Zakim]
Zakim has left #rdb2rdf
17:58:54 [Zakim]
... +49.322.22.aadd, nunolopes, soeren
17:59:01 [mhausenblas]
rrsagent, bye
17:59:01 [RRSAgent]
I see no action items