SODA1.0 WD release

[Mark Taylor]

Hi DAL,

I have one or two comments on the SODA-20151221 WD.

Sec 1.2:
   The structure/hierarchy of this section looks confusing, or possibly
   wrong.  It looks to me like everything in section 1 after section
   1.2 is a "motivating use case", but the document has a section 1.3
   at the same level as the Motivating Use Cases heading.  Is this
   spurious?

Sec 1:
   Most of the use cases in sec 1 are labelled "will be developed
   and supported in [a later SODA version]".  Does this mean that
   this version of SODA is only targetted at simple (POS/BAND/TIME/POL)
   cutouts?  That's fine if so, but it would be helpful to note that
   fact explicitly (possibly alongside aspirations for future extensions)
   somewhere in the introduction.  Alternatively, if it can do
   other things, a non-cutout use case that is supported by the
   current version could be included.

DALI and xtypes:
   sec 3.2.1: "the xtype can take one of the three values 'circle',
   'range' and 'polygon' as defined in DALI.";
   sec 3.2.2: "the xtype is 'interval' as defined in DALI."

   The reference in the bibliography is to DALI 1.0,
   and as far as I can tell, there are no references to
   xtype in DALI 1.0.  I've heard rumours that DALI 1.1 discusses
   xtypes, but I haven't seen that text.  If SODA is going to
   talk about DALI-defined xtypes (and there seem to be rather a
   lot of them here), it should reference a version of DALI
   that actually does define them.

arraysize values:
   sec 3.1.1: "In addition ... its datatype 'char', with arraysize '*'".
   I don't like mandating arraysize as "*".  There's no reason it
   shouldn't have an arraysize which is (e.g.) the exact length
   of the string.  Also, mandating datatype of char may come back
   to bite us if we do something datatype-dependent to accommodate
   unicode characters in the future.  I'd be inclined just to say
   it's a character array.  Similar remarks apply to POL (sec 3.2.4),
   which could reasonably have arraysize="1".

Finally (at least for now), it's not obvious to me from this document
how to actually use a SODA service.  Possibly that's because I'm
not familiar enough with Datalink or other associated standards,
but I may not be the only one...  Presumably (in view of the
language about xtypes, datatypes and arraysizes) you have to present
a VOTable to the service including the relevant parameters, but
it's not clear to me how to go about this.  Can you add a short
example section illustrating how you'd present a query to a SODA
service?

Mark


On Thu, 24 Dec 2015, François Bonnarel wrote:

> Dear DAL members,
>      This close-to-christmas email to announce that SODA1.0 (previously known
> as AccessData1.0) WD has been released last monday. See :
> http://www.ivoa.net/documents/SODA/20151221/index.html
>       There has been very long discussions among authors and we made some
> progress in convergence. However there is still points hardly debated. This is
> my responsability of editor as well as DAL chair to provide now a version
> which is regarded as insufficient according to some of us but is nonetheless
> fulfilling the CSP and community basic requirements according to me. Probably
> the discussion will start very soon on the DAL mailing list.
> 
> Best regards and Season greatings !!!
> François Bonnarel
> 

--
Mark Taylor   Astronomical Programmer   Physics, Bristol University, UK
m.b.taylor at bris.ac.uk +44-117-9288776  http://www.star.bris.ac.uk/~mbt/