ISSUE-72: Bring back R2RML lookup tables

lookup-table2

Bring back R2RML lookup tables

State:

POSTPONED

Product:

R2RML

Raised by:

Richard Cyganiak

Opened on:

2011-11-07

Description:

This is part of the LC feedback on R2RML from Dominique Guardiola:
http://lists.w3.org/Archives/Public/public-rdb2rdf-comments/2011Sep/0006.html

Before LC, work was done on a lookup table feature that allows translation from database values to arbitrary IRIs. Two different designs were proposed, one based on SKOS and one proprietary R2RML design. None of them made it into the LC spec, however.

Dominique says:

[[
I think this decision is a pity : if you look from the point of view of future R2RML end-users , translation tables are a common pattern, which is present, for example in most web development frameworks or CMSs.

Anyone making SQL database knows it's better to use integers columns instead of verbose labels in order to :

- speed up queries
- allow the renaming of these columns labels easily
- avoid typos when these columns are also keys (when there's no foreign key constraint : think of MyISAM, probably one of the most common DB storage)

The use of SKOS here is a false question : it's true this looks like a "controlled vocabulary" situation, but I'd follow the argument stating that having properties like rr:value, rr:term is simpler for RDF newbies. I mean, a vocabulary choice question should not prevent you to provide this kind of simple feature.
Allowing the table to be linked elsewhere is important too, but could be added later, as could be more complex mapping techniques.

But removing this simple tool, a 1:1 code-to-string or code-to-URI table, from being part of the recommandation would send IMHO a bad signal to newcomers , like "hey, they didn't even think of a straightforward way to do that?"

Having to do pre-queries in a R2RML view just to fetch some labels in a separate table (that perhaps doesn't even exists, the labels list being hardcoded in the application code) is not really an answer.
]]

Much of the discussion around the two designs is captured under ISSUE-61 and ISSUE-66.

Related Actions Items:

• ACTION-170 on Richard Cyganiak to Draft a compromise translation table design for ISSUE-72 - due 2011-11-19, closed

Related emails:

1. Re: 2011-12-20 meeting minutes (from michael.hausenblas@deri.org on 2011-12-21)
2. Re: ISSUE-57 and ISSUE-72 implemented (was: Re: 2011-12-20 meeting minutes) (from richard@cyganiak.de on 2011-12-20)
3. Re: 2011-12-20 meeting minutes (from richard@cyganiak.de on 2011-12-20)
4. ISSUE-57 and ISSUE-72 implemented (was: Re: 2011-12-20 meeting minutes) (from richard@cyganiak.de on 2011-12-20)
5. 2011-12-20 meeting minutes (from michael.hausenblas@deri.org on 2011-12-20)
6. Re: RDB2RDF WG agenda for 2011-12-20 meeting 1700 UTC (from unbehauen@informatik.uni-leipzig.de on 2011-12-20)
7. Re: RDB2RDF WG agenda for 2011-12-20 meeting 1700 UTC (from privera.salas@gmail.com on 2011-12-20)
8. Re: RDB2RDF WG agenda for 2011-12-20 meeting 1700 UTC (from ashok.malhotra@oracle.com on 2011-12-20)
9. RDB2RDF WG agenda for 2011-12-20 meeting 1700 UTC (from michael.hausenblas@deri.org on 2011-12-20)
10. Re: Some implementation experience on ISSUE-72 (translation tables) (from juanfederico@gmail.com on 2011-12-13)
11. Re: Comments needed – Re: Lookup table proposal (re ISSUE-72) (from richard@cyganiak.de on 2011-12-13)
12. Re: Comments needed – Re: Lookup table proposal (re ISSUE-72) (from juanfederico@gmail.com on 2011-12-13)
13. Re: Comments needed – Re: Lookup table proposal (re ISSUE-72) (from juanfederico@gmail.com on 2011-12-13)
14. Re: Comments needed – Re: Lookup table proposal (re ISSUE-72) (from richard@cyganiak.de on 2011-12-13)
15. Re: RDB2RDF WG agenda for 2011-12-13 meeting 1700 UTC (from marcelo.arenas1@gmail.com on 2011-12-13)
16. Re: RDB2RDF WG agenda for 2011-12-13 meeting 1700 UTC (from unbehauen@informatik.uni-leipzig.de on 2011-12-13)
17. Re: RDB2RDF WG agenda for 2011-12-13 meeting 1700 UTC (from bvillazon@fi.upm.es on 2011-12-13)
18. Re: Comments needed – Re: Lookup table proposal (re ISSUE-72) (from richard@cyganiak.de on 2011-12-13)
19. Re: Some implementation experience on ISSUE-72 (translation tables) (from richard@cyganiak.de on 2011-12-13)
20. Re: Comments needed – Re: Lookup table proposal (re ISSUE-72) (from richard@cyganiak.de on 2011-12-13)
21. RDB2RDF WG agenda for 2011-12-13 meeting 1700 UTC (from michael.hausenblas@deri.org on 2011-12-13)
22. Re: Comments needed – Re: Lookup table proposal (re ISSUE-72) (from juanfederico@gmail.com on 2011-12-12)
23. Re: Some implementation experience on ISSUE-72 (translation tables) (from juanfederico@gmail.com on 2011-12-12)
24. Some implementation experience on ISSUE-72 (translation tables) (from richard@cyganiak.de on 2011-12-12)
25. Comments needed – Re: Lookup table proposal (re ISSUE-72) (from richard@cyganiak.de on 2011-12-12)
26. Lookup table proposal (re ISSUE-72) (from dmcneil@revelytix.com on 2011-12-10)
27. Re: Revised SKOS-based translation table proposal (from SOURIPRIYA.DAS@oracle.com on 2011-11-27)
28. Re: Agenda W3C RDB2RDF Working Group telephone conference 2011-11-22 (from nuno.lopes@deri.org on 2011-11-22)
29. Re: Agenda W3C RDB2RDF Working Group telephone conference 2011-11-22 (from marcelo.arenas1@gmail.com on 2011-11-22)
30. Re: Agenda W3C RDB2RDF Working Group telephone conference 2011-11-22 (from SOURIPRIYA.DAS@oracle.com on 2011-11-22)
31. Re: Agenda W3C RDB2RDF Working Group telephone conference 2011-11-22 (from dmcneil@revelytix.com on 2011-11-22)
32. Re: Agenda W3C RDB2RDF Working Group telephone conference 2011-11-22 (from ivan@w3.org on 2011-11-22)
33. Re: Agenda W3C RDB2RDF Working Group telephone conference 2011-11-22 (from boris.villazon@terrazas.name on 2011-11-22)
34. Re: Revised SKOS-based translation table proposal (from richard@cyganiak.de on 2011-11-21)
35. Re: Revised SKOS-based translation table proposal (from SOURIPRIYA.DAS@oracle.com on 2011-11-21)
36. Agenda W3C RDB2RDF Working Group telephone conference 2011-11-22 (from ashok.malhotra@oracle.com on 2011-11-21)
37. Re: Revised SKOS-based translation table proposal (from ivan@w3.org on 2011-11-15)
38. Revised SKOS-based translation table proposal (from richard@cyganiak.de on 2011-11-15)
39. Status update on LC comments and post-LC changes to R2RML (from richard@cyganiak.de on 2011-11-07)
40. ISSUE-73 (section11-cleanup): Section 11 cleanup [R2RML] (from sysbot+tracker@w3.org on 2011-11-07)
41. ISSUE-72 (lookup-table2): Bring back R2RML lookup tables [R2RML] (from sysbot+tracker@w3.org on 2011-11-07)

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