<trackbot> Date: 24 November 2009

<mhausenblas> scribenick: Marcelo

<mhausenblas> (as of http://www.w3.org/2001/sw/rdb2rdf/wiki/ScribeList)

Admin

<mhausenblas> ACTION-15?

<trackbot> ACTION-15 -- Harry Halpin to make a draft scribelist on wiki -- due 2009-11-24 -- OPEN

<trackbot> http://www.w3.org/2001/sw/rdb2rdf/track/actions/15

<mhausenblas> close ACTION-15

<trackbot> ACTION-15 Make a draft scribelist on wiki closed

<mhausenblas> ACTION-16?

<trackbot> ACTION-16 -- Juan Sequeda to init DDL coverage on Wiki -- due 2009-11-24 -- OPEN

<trackbot> http://www.w3.org/2001/sw/rdb2rdf/track/actions/16

<mhausenblas> close ACTION-16

<trackbot> ACTION-16 Init DDL coverage on Wiki closed

<mhausenblas> ACTION-17?

<trackbot> ACTION-17 -- Michael Hausenblas to create an issue for vendor-specific data types -- due 2009-11-24 -- OPEN

<trackbot> http://www.w3.org/2001/sw/rdb2rdf/track/actions/17

Liaisons

<mhausenblas> ISSUE-2?

<trackbot> ISSUE-2 -- R2RML serializations -- OPEN

<trackbot> http://www.w3.org/2001/sw/rdb2rdf/track/issues/2

<mhausenblas> http://www.w3.org/2001/sw/rdb2rdf/wiki/Liaisons

<Souri> Eric volunteers to take over RIF and OWL liaisons

Ultrawrap presentation

<jsequeda> http://www.cs.utexas.edu/~jsequeda/UltrawrapPresentationW3CRDB2RDF.pdf

slide #2

goals of ultrawrap ..

automatically create SPARQL endpoints for legacy relational databases

real-time consistency between relational and RDF

slide #3

<mhausenblas> s/yes, but I need a bit of help/Topic: Ultrawrap presentation

architecture of ultrawrap

<Souri> an alternative: SPARQL querying of relational data

compite time ... create ontology and virtual triple store

run time ... SPARQL to SQL

slide #4

architecture of ultrawrap

slide #5 and #6

first step of the architecture

putative ontology is created automatically from source relational schema

who is taking? how can I know that?

<Souri> ashok

slide #7

<Souri> +q

first-order logic rules transform SQL DDL to OWL

rules cover all possible combination from DDL

slide #8

articles where the approach of ultrawrap is described

<Zakim> ericP, you wanted to (eventually) ask about the differences between RDF and OWL access (SPARQL vs. OWL API?)

Souri: Do you read the data dictionary to get information about DDL?

jsequeda: yes, we do

slide #9

Relational example about students and courses

slide #11

Proof of total coverage of all key combinations

slide #12

All possible combinations of keys and foreign keys are produced (described by a tree)

All these combinations are considered by ultrawrap

Ultrawrap rules are complete in the sense that considered all possible alternatives of keys and foreign keys

This is shown in the DEXA paper mentioned in slide #8

<Zakim> ericP, you wanted to ask if any were degerate forms a la "i don't care if there are 0, 1 or more elts with this identifier"

<Souri> Are you talking about constraint violations in the actual data?

slide #14

the putative ontology is created from the data dictionary

Ahmed: Could you please say a bit more about the rules?

<Souri> +q

slide #15

what is the quality of the putative ontology?

<Souri> -q

If the quality is sufficient, just renaming is needed

If it is not, putative ontology need to be mapped to a domain ontology

slide #16

virtual triple store

represent relational data as triples

virtual triple store uses a table with tree columns: subject, predicate and object

it actually uses a table with five columns (include index values)

slide #18

example of a select statement that output triples

<Souri> +q

thanks: -)

<MacTed> Marcelo - the voice you couldn't recognize was Orri

slide #19

triple view is a union of all the select statements that output triples

slide #20

SPARQL to SQL

slide #21

shows a naive translation of a SPARQL query into SQL

it is a syntactic transformation

this happens in run time

slide #22

SQL optimizer

slide #23

<Souri> -q

shows some examples of query optimization in the system

slide #24

shows the query plans

scribe: triple view plan and optimal plan

<Souri> As I had indicated on 17-Nov-2009 meeting (see minutes) , we'd like very much to present our SQL-based approach on 01-Dec-2009

<mhausenblas> Souri, yes, we'll discuss this in AOB

<Souri> thanks michael

slide #25

summary of what happens in compile and run time

slide #26

shows experimental results

running on Microsoft SQL Server

<Souri> Are these hot (back-to-back) runs?

Test on BSBM on 1 million triples

Comparison was made with Jena

slide #27

Current work

<MacTed> so *most* of those numbers were calculated from published results ... only a couple were actually run

Version 0 of the system was presented (query only the putative ontology)

<mhausenblas> Michael: Ultrawrap is faster than native SQL (Q5 and Q10)?

I lost the phone connection

AOB

<mhausenblas> scribenick: mhausenblas

http://www.w3.org/2001/sw/rdb2rdf/wiki/Initial_Round_of_Presentations

Michael: collision OKKAM and Oracle

<Marcelo> I am back :-)

PROPOSAL: Oracle 1 Dec, Eric 8 DEc and OKKAM 15 dec

<Souri> +1

<angela_UNITN> +1

<Marcelo> +1

[adjourned]

This is scribe.perl Revision: 1.135  of Date: 2009/03/02 03:52:20  
Check for newer version at http://dev.w3.org/cvsweb/~checkout~/2002/scribe/

Guessing input format: RRSAgent_Text_Format (score 1.00)

Succeeded: s/yes, but I need a bit/Topic: Ultrawrap presentation/
FAILED: s/yes, but I need a bit of help/Topic: Ultrawrap presentation/
Succeeded: s/Ultrawrap presentation of help/Ultrawrap presentation/
Succeeded: s/thanks./Topic: Admin/
Succeeded: s/continues - Michael is a slacker ;)/Topic: Liaisons/
Succeeded: s/Could you please put the URL for the slides on IRC?/Eric volunteers to take over RIF and OWL liaisons/
Found ScribeNick: Marcelo
Found ScribeNick: mhausenblas
Inferring Scribes: Marcelo, mhausenblas
Scribes: Marcelo, mhausenblas
ScribeNicks: Marcelo, mhausenblas
Default Present: Ashok_Malhotra, +043316876aaaa, +7.791.000.0.aabb, +1.512.471.aacc, [IPcaller], +1.781.273.aadd, +1.603.897.aaee, +1.508.358.aaff, MacTed, whalb, +3539149aagg, jsequeda, Souri, mhausenblas, nunolopes, +39.046.188.aahh, EricP, cygri
Present: Ashok_Malhotra +043316876aaaa +7.791.000.0.aabb +1.512.471.aacc [IPcaller] +1.781.273.aadd +1.603.897.aaee +1.508.358.aaff MacTed whalb +3539149aagg jsequeda Souri mhausenblas nunolopes +39.046.188.aahh EricP cygri
Regrets: Harry Ben
Agenda: http://lists.w3.org/Archives/Public/public-rdb2rdf-wg/2009Nov/0056.html
Found Date: 24 Nov 2009
Guessing minutes URL: http://www.w3.org/2009/11/24-RDB2RDF-minutes.html
People with action items: 

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