FreeFormat < IVOA

   + Free Format data model fields and extensibility mechanism

When a data provider cannot use the proposed value fields (for instance in data product type), how can he/she still provide some information to characterise his/her data sets?

   1. *How could we allow for extensibility?*  If we need to consider new kinds of science data product , not yet defined in the !ObsTAP fields , how should we proceed?
   1. *Description of a data set* - =obs_title=. In !ObsTAP , it is not a mandatory field, it could become important in future releases if its usage is well-defined. At the moment it is just free-format, and that could be an issue.

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Regarding extensibility, I think we should take the advice of IVOA.MarkusDemleitner regarding IVOA.DataProduct, and have the values added as IVOA-controlled and registered enumerations. If possible, both a hierarchical and yuxtapositional notation (à la UCD) should be used.

Regarding =obs_title=, I do not think we should rely on it for discovery. We should try to push for =obs_creator_did=, or at least for =obs_publisher_did=, as the ways for PIs to refer to VO datasets in their literature. Conversely, use of bib_reference should be allowed for discovery, and substituted by a VARCHAR(19) (length of a bibcode), or bigger if DOIs where to be allowed (something like VARCHAR(2048) should cover most ground for existing DOIs. 

-- IVOA.JuanDeDiosSantanderVela - 07 Mar 2011

As far as I understand obs_title is a free text description. Maybe usefull but the field name is confusing I think. Nothing to do with 
an ID.

-- IVOA.FrancoisBonnarel - 15 Mar 2011 




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This topic: IVOA > WebHome > IvoaDataModel > ObsDMCoreComponents > FreeFormat
Topic revision: r7 - 2011-03-16 - FrancoisBonnarel