DM Workshop wrap-up

[Laurent Michel]

Hello,

Here is my take after having read this thread.
I'll open an issue on https://github.com/ivoa-std/VOTable/ for the follow-up

VODML block
===========
- follows a separate schema
- prefixed with a specific name space e.g. <dm_mapping:VODML>
- enclosed in a <RESOURCE type="meta">

VODML resource location
=======================
My take is that there is no need to support multiple VODML blocks since the mapping syntax is not model-dependant. Assuming that 
dealing with annotated VOTables is an extra job for both data providers and client developers, let's keep this job as simple as 
possible. Our first use-case is to improve the meta-data representation and it look wise to keep this in mind and not to bother 
our-self with more complex features e.g. involving mappings on multiple models:

- The VODML RESOURCE must be enclosed in another RESOURCE
- The VODML RESOURCE must be the first child of the host RESOURCE
   - thus maxOccur=1 by construction
- The scope of the mapping blocks covers the whole content of that host RESOURCE

QUESTION:
- What are the consequences of such rules on both VOTable schema and standard?

The TOPCAT session issue
========================
My take:
- The structure of the mapping should easily (*) support the merge of different mapping blocks since it is based on TEMPLATES 
that are table-specific.
- The GLOBALS contents can be merged
- The TEMPLATES from all tables can be stacked

Let's take an example:

Votable #1:
RESOURCE
   RESOURCE
    VODML
      GLOBALS
         globals_1
      TEMPLATE (tableref=1_1)
      TEMPLATE (tableref=1_2)
  TABLE (ID=1_1)
  TABLE (ID=1_2)

Votable #2:
RESOURCE
   RESOURCE
    VODML
      GLOBALS
         globals_2
      TEMPLATE (tableref=2_1)
      TEMPLATE (tableref=2_2)
  TABLE (ID=2_1)
  TABLE (ID=2_2)

Topcat session:

RESOURCE
   RESOURCE
    VODML
      GLOBALS
         globals_1
         globals_2
      TEMPLATE (tableref=1_1)
      TEMPLATE (tableref=1_2)
      TEMPLATE (tableref=2_1)
      TEMPLATE (tableref=2_2)
  TABLE (ID=1_1)
  TABLE (ID=1_2)
  TABLE (ID=2_1)
  TABLE (ID=2_2)

- Difficulties will arrive when the same IDs will be used by both VOTables; but this is an issue even without VODML mapping.


Laurent

(*): in theory at least


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jesuischarlie/Tunis/Paris/Bruxelles/Berlin

Laurent Michel
SSC XMM-Newton
Tél : +33 (0)3 68 85 24 37
Fax : +33 (0)3 )3 68 85 24 32
Université de Strasbourg <http://www.unistra.fr>
Observatoire Astronomique
11 Rue de l'Université
F - 67200 Strasbourg