ISSUE-69: datatype sizes

datatype sizes

datatype sizes

State:

CLOSED

Product:

Raised by:

Eric Prud'hommeaux

Opened on:

2011-09-30

Description:

http://www.w3.org/2001/sw/rdb2rdf/track/issues/48 was resolved by following the SQL spec's lead for generating XML from SQL datatypes. Unfortunately, these mappings are all subject to vender-specific width limitations, which means that implementors have no idea what to implement in order to interoperate with other implementations. The Direct Mapping LC provides fixed numbers for these mappings,
http://www.w3.org/TR/2011/WD-rdb-direct-mapping-20110920/#defn-literal_map
but these have not been subject to WG review. Justifications for these selections were:
type width reason
xsd:decimal 18 http://www.w3.org/TR/2001/REC-xmlschema-2-20010502/#decimal says minimum is 18
xsd:integer 18 lexical restriction of decimal doesn't affect width
xsd:double 23 maximum characters for an IEEE754 double (i.e. xsd:double)
xsd:date 13 limited to under 100k years, e.g. +100000-01-01
xsd:time 23 10E-14 second precision, e.g. 01:23:45.67890123456789
xsd:dateTime 37 sizeof(xsd:date)+sizeof("T")+sizeof(xsd:time)

The choices of 10E6 years and 10E-14 seconds are arbitrary. We could limit to common cases like CCYY for years, and microsecond precision for time, noting that extensions to dates should follow the conventions in ISO8601. That would reduce widths to 10 and 15, putting dateTimes as 26.

Related Actions Items:

• ACTION-168 on Richard Cyganiak to Rewrite R2RML datatypes section, add note on partial XSD implementations, and draft a PROPOSAL to close ISSUE-69 - due 2011-11-19, closed

Related emails:

1. Re: definition of natural mapping (from eric@w3.org on 2012-01-11)
2. Re: definition of natural mapping (from richard@cyganiak.de on 2012-01-11)
3. Re: Request for comments: Breaking down the datatype mapping problem (ISSUE-69) (from richard@cyganiak.de on 2011-11-21)
4. Re: Request for comments: Breaking down the datatype mapping problem (ISSUE-69) (from dmcneil@revelytix.com on 2011-11-21)
5. Re: Request for comments: Breaking down the datatype mapping problem (ISSUE-69) (from richard@cyganiak.de on 2011-11-21)
6. Re: Request for comments: Breaking down the datatype mapping problem (ISSUE-69) (from dmcneil@revelytix.com on 2011-11-21)
7. Re: Request for comments: Breaking down the datatype mapping problem (ISSUE-69) (from unbehauen@informatik.uni-leipzig.de on 2011-11-21)
8. Re: Request for comments: Breaking down the datatype mapping problem (ISSUE-69) (from richard@cyganiak.de on 2011-11-21)
9. Re: Request for comments: Breaking down the datatype mapping problem (ISSUE-69) (from unbehauen@informatik.uni-leipzig.de on 2011-11-17)
10. Re: Request for comments: Breaking down the datatype mapping problem (ISSUE-69) (from richard@cyganiak.de on 2011-11-16)
11. Re: Request for comments: Breaking down the datatype mapping problem (ISSUE-69) (from rodriguez@inf.unibz.it on 2011-11-16)
12. Request for comments: Breaking down the datatype mapping problem (ISSUE-69) (from richard@cyganiak.de on 2011-11-15)
13. Canonical forms for literals in SQL vs XSD (from richard@cyganiak.de on 2011-11-15)
14. Proposal for shared SQL-to-XSD mapping for DM + R2RML (from richard@cyganiak.de on 2011-11-14)
15. Re: RDB2RDF WG agenda for 2011-10-18 meeting 1600 UTC (from juanfederico@gmail.com on 2011-10-18)
16. Re: RDB2RDF WG agenda for 2011-10-18 meeting 1600 UTC (from marcelo.arenas1@gmail.com on 2011-10-18)
17. RDB2RDF WG agenda for 2011-10-18 meeting 1600 UTC (from michael.hausenblas@deri.org on 2011-10-18)
18. Re: Issue-69 (from richard@cyganiak.de on 2011-10-11)
19. Re: RDB2RDF WG agenda for 2011-10-11 meeting 1600 UTC (from SOURIPRIYA.DAS@oracle.com on 2011-10-11)
20. Issue-69 (from ashok.malhotra@oracle.com on 2011-10-11)
21. Re: RDB2RDF WG agenda for 2011-10-11 meeting 1600 UTC (from seema.sundara@oracle.com on 2011-10-11)
22. Re: RDB2RDF WG agenda for 2011-10-11 meeting 1600 UTC (from marcelo.arenas1@gmail.com on 2011-10-11)
23. Re: RDB2RDF WG agenda for 2011-10-11 meeting 1600 UTC (from richard@cyganiak.de on 2011-10-11)
24. Re: RDB2RDF WG agenda for 2011-10-11 meeting 1600 UTC (from nuno.lopes@deri.org on 2011-10-11)
25. Re: RDB2RDF WG agenda for 2011-10-11 meeting 1600 UTC (from ivan@w3.org on 2011-10-11)
26. RDB2RDF WG agenda for 2011-10-11 meeting 1600 UTC (from michael.hausenblas@deri.org on 2011-10-11)
27. Re: ISSUE-69 (datatype sizes): datatype sizes (from richard@cyganiak.de on 2011-10-04)
28. Re: ISSUE-69 (datatype sizes): datatype sizes (from eric@w3.org on 2011-10-02)
29. Re: ISSUE-69 (datatype sizes): datatype sizes (from richard@cyganiak.de on 2011-10-02)
30. Re: ISSUE-69 (datatype sizes): datatype sizes (from eric@w3.org on 2011-10-01)
31. Re: ISSUE-69 (datatype sizes): datatype sizes (from richard@cyganiak.de on 2011-09-30)
32. ISSUE-69 (datatype sizes): datatype sizes (from sysbot+tracker@w3.org on 2011-09-30)

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