[ObsCoreRFC]Minutes of the telco Monday June 6

[Arnold Rots]

Mireille,

I am sorry I could not attend - I was in a meeting that took much
longer than expected.

I am still left with a few questions, though they may be minor and
perhaps not even controversial.

1. I puzzled over the comment on whether polarization information
should be mandatory. The logic applied seems to lead to the assumption
that all datasets that do not provide a particular optional item will
return an error as soon as that item is in the query.
I would have assumed that the behavior SHOULD be:
- if a particular item in the SELECT clause is not available from a
service, that service SHALL return a NULL value.
- if a particular item in the WHERE clause is not available from a
service, that service SHALL return an empty list of results.
Under that assumption, there should not be any problem in making
polarization optional.

2. bib_reference
I stumbled over this and it looks like I probably misinterpreted it.
It is meant to be a documentation reference for the
service/collection/repository, right?
However, if that is the case, the description in B.4.3 is misleading:
"This is a forward link to publications which reference the dataset."
That indicates that it would be for a specific dataset in the
collection (e.g., a scientific paper on that observation), which is
quite a different beast.

3. dataproduct_type, dataproduct_subtype, access_format
I still think the scheme that is proposed is incomplete since it is
ill-suited (as currently defined) to accommodate datasets (i.e.,
collections of files).
I would like to suggest that it would be good to add a
dataproduct_type "package" (or some such thing) that indicates that
the client will be receiving not just a single file. However, the
client will still want to know what is in the package, so maybe the
subtype should contain a list of the science file data types?
In access format we are running into a somewhat similar problem:
it's nice (and necessary) to know that a tar file is coming, but it is
equally important to know what kinds of formats are hidden inside that
tar file: if it is, say, Cobol code, I am not interested. Should it be
a comma separated list? Or something like "tar(fits,pdf,txt)"?

4. access_estsize: compressed or expanded?

5. access_url
Should this be a direct download URL or would a "landing place"
suffice? That is especially relevant for packages, where one might
have a choice of package compositions.

  - Arnold



Mireille Louys wrote:
[ Charset ISO-8859-1 unsupported, converting... ]
> Dear all ,
> 
> I uploaded the minutes of the teleconference on the revision of the  
> ObsCore DM proposed recommendation.
> Please look at the bottom of the RFC page :
> http://www.ivoa.net/cgi-bin/twiki/bin/view/IVOA/ObsCoreRFC
> 
> Thanks , Mireille
> 
> 
> 
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Arnold H. Rots                                Chandra X-ray Science Center
Smithsonian Astrophysical Observatory                tel:  +1 617 496 7701
60 Garden Street, MS 67                              fax:  +1 617 495 7356
Cambridge, MA 02138                             arots at head.cfa.harvard.edu
USA                                     http://hea-www.harvard.edu/~arots/
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