RDB2RDF Working Group Teleconference

29 Oct 2009


See also: IRC log


Souri, mhausenblas, marcelo , Seema, whalb, +039046188aabb, hhalpin, Ashok_Malhotra, +049341973aacc, nunolopes, soeren




<trackbot> Date: 29 October 2009

-> previous http://www.w3.org/2009/10/22-RDB2RDF-minutes.html

<scribe> Scribenick: mhausenblas

<Ahmed> Hi Harry

ahm, hhalpin am I scribing or you?

well, then ..

please leave it to me - there are plenty of useless topics on the agenda, hence ...


<angela> 039046188aabb is Angela

PROPOSAL: accept minutes of previous telecon http://www.w3.org/2009/10/22-RDB2RDF-minutes.html

<soeren> +soeren

<soeren> aacc is soeren

<hhalpin> +1

<Souri> For Triplify presentation, are we using the 22-slide pdf file?

RESOLUTION: minutes from last telecon accepted

ACTION review


Ashok: next week is TPAC

<soeren> http://www.w3.org/2001/sw/rdb2rdf/wiki/images/6/6d/Triplify.pdf

<soeren> that's the triplify presentation

<hhalpin> +1 to skipping telecon next week.

<hhalpin> Then we also get to reconfigure time today.

yes, indeed


<trackbot> ACTION-8 -- Harry Halpin to double-check EricP's status and have him send in his proposals about mapping -- due 2009-10-29 -- OPEN

<trackbot> http://www.w3.org/2001/sw/rdb2rdf/track/actions/8

close ACTION-8

<trackbot> ACTION-8 Double-check EricP's status and have him send in his proposals about mapping closed



<trackbot> ACTION-10 -- Harry Halpin to will add 10 more participants to telecon -- due 2009-10-29 -- OPEN

<trackbot> http://www.w3.org/2001/sw/rdb2rdf/track/actions/10

close ACTION-10

<trackbot> ACTION-10 Will add 10 more participants to telecon closed

<hhalpin> close ACTION-11

<trackbot> ACTION-11 Ask EricP for back-up closed


<hhalpin> Notes "The mapping language MUST define the set of relational algebra to be supported in the first release. This set to be supported SHOULD be as complete as possible and be defined as soon as possible after the WG official launch."

<hhalpin> I expect that we should have Marcelo give a presentation on his work on formal semantics ASAP after we're done with the implementation overviews.

T+4: Requirements and Use Cases for the RDB2RDF Mapping Language (R2RML)

Presentation of Triplify

slides see http://www.w3.org/2001/sw/rdb2rdf/wiki/images/6/6d/Triplify.pdf

<Souri> About the requirements 'SHOULD' portion: What is "human-readable"? Is SQL query human-readable?

soeren: our group works on couple of tools (DL Learner, etc.) as well as onTriplify

slide 2

TriplifyBig Picture

slide 3


many DB-backed applications

idea: when we're able to RDFise the content of these DB, we gain quite a bit - Web of Data

most of the tools are OSS, should be easy to integrate

slide 4

configure once, use often

slide 5

solution: uses SQL to transform

extends SQL with some syntactic constructs

maps URI patterns to set of SQL patterns

according to the Linked Data principles

slide 6

Ashok: will you talk about the extensions?

soeren: yes
... just some conventions, actually
... few tables anyway, no automatic generation, hence
... conventions, such as first col must be an ID, the col name should refer to RDF properties

Souri: conceptual mapping or materialising?

soeren: view

slide 7

soeren: here is an example mapping a WP blog post


SELECT id, post_authorAS 'sioc:has_creator->user',

post_title AS 'dc:title',

post_content AS 'sioc:content', post_date AS


post_modified AS 'dcterms:created^^xsd:dateTime'

FROM posts

WHERE post_status='publish‘ (ANDid=xxx)

Souri: we took the same approach
... our work was so far only internally
... there are two approaches to address the datatype

soeren: needed to overwrite the default (Triplify supports both)

Souri: I think we need a consistency check - explicit might be more benfical

slide 8

shows the actual RDF conversion

slide 9

summarises the implementation of Triplify

design principle is KISS

no new mapping language (SQL is used)

available for popular languages

works with most DBs

slide 10

an example of an WP blog configuration

nine queries

slide 11

we offer a configuration repository

slide 12

slide 13

two extensions

a temporal extension

address the 'when to crawl data'

slide 14

shows how this works in Triplify

Michael: would be good to know the update voc URI

slide 15

LOD update log generation

<Souri> LOD means ???

slide 16

Linked Open Data

Spatial Extension

<Souri> Thanks.


see linkeddata.org

soeren: used the spatial extension to create linked data version of OpenStreetMap

slide 17

example from http://linkedgeodata.org/

Souri: which query interface do you support?

soeren: based on URIs

skip to slide 19

RDB2RDF tool comparison

Triplify, D2R and Virtuoso views

slide 20

soeren: Triplifysupports the “long tail” of deployed Web applications
... that's it - questions?

<soeren> http://www2009.eprints.org/63/

Ashok: license?

soeren: it's OSS
... more background on Triplify see WWW paper above, will send to list and update Wiki

Meeting schedule


hhalpin: did the voting

<hhalpin> 11 EST

<hhalpin> Which would be 8AM EST on Tuesday.

<hhalpin> 8AM PST Tuesday 11 EST.

<hhalpin> Ashok - you can do 9AM Tuesday but not 8AM.

<Ashok> That is correct

<Souri> 9am PST, 12 noon EST Tues

<Ashok> Souri, I hope that's OK for you

everyone should check with http://www.timeanddate.com/worldclock/converter.html

<Souri> Ashok it is okay for me

<hhalpin> 5:00 PM GMT.

<hhalpin> http://www.timeanddate.com/worldclock/fixedtime.html?day=10&month=11&year=2009&hour=9&min=0&sec=0&p1=224

<scribe> ACTION: hhalpin to inform li ma [recorded in http://www.w3.org/2009/10/29-RDB2RDF-minutes.html#action01]

<trackbot> Created ACTION-12 - Inform li ma [on Harry Halpin - due 2009-11-05].

next meeting is on Tuesday 10 November 2009 at 17:00 GMT

<hhalpin> RESOLVED: To meet 10 Nov. 2009 17:00 UTC.

<hhalpin> take care!

<hhalpin> trackbot, end meeting

Summary of Action Items

[NEW] ACTION: hhalpin to inform li ma [recorded in http://www.w3.org/2009/10/29-RDB2RDF-minutes.html#action01]
[End of minutes]

Minutes formatted by David Booth's scribe.perl version 1.135 (CVS log)
$Date: 2009/11/06 00:11:21 $