Use case analysis for handling data cubes in VO

[Doug Tody]

On Tue, 28 Mar 2006, Markus Dolensky wrote:
> Two comments on DAL aspects of Mireille's and Francois' proposal:
>
> 1. mime types
>
>> AccessAndViewsProductType:
>> cube, image, spectrum, catalog, metadata
>> Different from the DataSetType of the DataSEt itself, because it
>> is the  Type of the Specific view. It includes also catalog, as a
>> result of source extraction and metadata to allow the retrieval of
>> full metadata descriptions such as characterisation ...
>
> Let's just use recognized values like application/fits, application/xml, 
> image/png etc. Unregistered types can be flagged with a "x-" as in 
> application/x-votable+xml.

I agree that for MIME types we should stick with defined types.

However:

     application/fits etc. refer to file formats

     image, spectrum, catalog, etc. (or whatever the names end up being)
     are object types defined by DAL, with associated data models etc.

Hence what we are actually talking about here is probably not a MIME type.

An example of the difference:  FITS and VOTable are file formats, used as
data containers for many different kinds of objects.  In principle any
of our object types can be stored in these containers.  In fact the identical
object can be stored in either format, hence object types and file formats
are independent.  We can often retrieve a given object in any of several
different file formats.

 	- Doug