Spectrum data model

[Matthew Graham]

Mark Taylor wrote:
> On Wed, 13 Sep 2006, Matthew Graham wrote:
>
>   
>> Hi,
>>     
>>> Otherwise, it seems to me that what is called for is an additional
>>> field in the SSAP response which names the specific serialization 
>>> format, if known.  This would require assigning some sort of name
>>> to the XML, FITS and VOTable formats defined in the Spectral DM
>>> document (presumably a URI of some sort).
>>>
>>> Mark
>>>       
>> The VOSpace specification uses uris to identify data formats and the 
>> idea is that these will be registered somewhere, e.g. 
>> ivo://net.ivoa.vospace/views/fits-table. It would make sense for both 
>> groups at least to use the same uris.
>>     
>
> Matthew
>
> Dave Morris made this point to me at the VOTech meeting in Strasbourg
> last week, but I'm not sure I was thinking very clearly about it at
> the time.  A question which occurs to me now: does VOSpace require 
> a single data format per file (or entry, or whatever the correct 
> term is), or can a single file be labelled with multiple different 
> data format URIs at the same time?
>
> Mark
>
>   
Hi,

If the data object is stored in a StructuredDataNode then multiple data 
views are allowed: this is, of course, implementation dependent but the 
idea is that if a VOSpace supported this, a FITS image might be 
retrievable as a JPEG or a GIF, etc. or a FITS table as a VOTABLE or CSV.

If the data object is stored in an UnstructuredDataNode then essentially 
bits in = bits out so only one view is allowed and that is the input view.

    Cheers,

    Matthew