W3C

- DRAFT -

RDB2RDF May 23, 2008

23 May 2008

See also: IRC log

Attendees

Present
Soeren Auer, Andrew_Eisenberg, Joe Betz, Kate Byrne, Ahmed Ezzat, Li Ma, Ashok_Malhotra, Jenny Green, AxelPolleres, Satya Sahoo, Dan Brickley
Regrets
Wolfgang Halb, Krishna Kulkarni, Catherine Dolbear
Chair
Ashok
Scribe
AndrewE

Contents


 

 

<Ashok> Andrew, can I impose upon you to scribe today?

Sure

<Ashok> Thanks!

<Ashok> scribenick: AndrewE

<AxelPolleres> I just joined together with Richard.

<joebetz> +1.509.771.aabb is Joe Betz

<cygri> slides: http://richard.cyganiak.de/2008/05/rdb2rdf-slides.pdf

<AxelPolleres> ivan is on skype

<scribe> New members Dan Brickley and Davide Palmisano

Last week's minutes: http://lists.w3.org/Archives/Public/public-xg-rdb2rdf/2008May/0014.html

approved

4. XG Logistics

Cancel June 6 Telcon?

Askok and Andrew will not be able to attend

<danbri> Re who attends http://www.eswc2008.org/

<danbri> I'll be there, also Axel, Jenny, ...

June 6 call is cancelled

Can Li Ma present June 13?

Li Ma says that he can

5. Action Items:

a. Whole group to start thinking about what the group wants to include

in the final output from the group.

b. Whole group to start thinking about what the group wants to include

in the final output from the group in terms of standards.

c. Whole group to provide comments on the state of the art that has now

been put up on the wiki page.

a,b,c are ongoing

d. Soeren to send mail re. standardizing an update interface

this has been done

Ashok: There is no SPARQL update specification

Ashok will reply to Soeren's email

<AxelPolleres> SPARQL update is one of the likely firsdt targets of a continuation of DAWG, if one may believe rumors...

<AxelPolleres> ;-)

<Ashok> Soeren's mail: http://lists.w3.org/Archives/Public/public-xg-rdb2rdf/2008May/0018.html

<soeren> http://lists.w3.org/Archives/Public/public-xg-rdb2rdf/2008May/0018.html

6. Satya Sahoo and Wolfgang Halb – Update on Literature Survey

Satya: Link to Learning Highly Structured ... is missing

<ssahoo2> RDB2Onto: Cerbah, F

<ssahoo2> publication details: "Learning Highly Structured Semantic Repositories from Relational Databases - demo paper", Proceedings of the 5th European Semantic Web Conference (ESWC 2008), Tenerife, Spain, Accepted - to be published in June, 2008.

Invite Cherba to meeting on June 20

7. Presentation by Richard Cyganiak on D2RQ

<cygri> http://richard.cyganiak.de/2008/05/rdb2rdf-slides.pdf

<Ashok> http://richard.cyganiak.de/2008/05/rdb2rdf-slides.pdf

<danbri> (i'd love to see it released under w3c license...)

download rate accelerated when SPARQL support was added

Users request ability to add subqueries in from and where clause

also ability to use type codes translations

d2rq: condition provides a SQL fragment, but subqueries may be problematic

<danbri> slide15: map:mbox_sha1 a d2rq:PropertyBridge; d2rq:sqlExpression “SHA1(CONCAT(‘mailto:’, User.email))”; d2rq:property foaf:mbox_sha1sum .

<danbri> cute :)

<danbri> richard "if we redesigned the language from scratch, we'd get schema data from jdbc and not require it in the mapping file"

Ashok: Can we have a pointer to D2RQ documentation?

Richard: We have not given much thought to update

<danbri> (imho, steer clear of update... )

<danbri> q: do you support named graphs?

?: Do you support named graphs?

<danbri> a: no, it all goes into default graph surrently

Richard: No

Jenny: How much effort is being spent on improvements?

Richard: Maintaining it in my spare time, no new features

q: Does D2RQ create indices in order to improve performance?

Richard: No, but generated SQL will use existing indices

q: Can additional metadata from database be used?

Richard: Data types can now be extracted
... use of primary key or uniqueness could allow us to generate better performing SQL
... It would be possible to define a mapping by providing a delta to auto-generated mapping

q: To what extent can mapping be pushed into view definitions?

Richard: We assumed that D2RQ would not modify the database

MySQL did not provide temporary views

<cygri> D2RQ manual: http://www4.wiwiss.fu-berlin.de/bizer/D2RQ/spec/

<cygri> D2RQ homepage: http://www4.wiwiss.fu-berlin.de/bizer/d2rq/

8. Future presentations

- - Huajun Chen on DartGrid May 30

9. AOB

<AxelPolleres> Thanks! bye!

<cygri> thanks all!

Summary of Action Items

[End of minutes]

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Default Present: Andrew_Eisenberg, +1.937.775.aaaa, +1.509.771.aabb, +1.781.904.aacc, Ashok_Malhotra, +1.408.285.aadd, AxelPolleres, [IBM_Watson], danbri
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Got date from IRC log name: 23 May 2008
Guessing minutes URL: http://www.w3.org/2008/05/23-rdb2rdf-minutes.html
People with action items: 

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