SODA1.0 WD release

[François Bonnarel]

Hi all,
     Thanks for your email, Mark.
On 08/01/2016 23:39, Mark Taylor wrote:
> 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.
I think you are right. We have to enhance that this version is targetted 
at simple cutouts. The other future motivations have to be clarified in 
a specific introduction section .
>
> 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.
DALI 1.1 will be proposed soon by Pat, I guess. But you are right, this 
is a problem we have with modularity in DAL. DAL protocols rely on each 
other but their development is parallel and not always in phase. This 
has two possible drawbacks : either redondancy of text or possible 
confusion on where the information is. Will try to fix that.
>
> 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".
I am waiting for additional advices on this
> 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?
Hummm... The basic usage is not by presenting a VOTABLE but by using an 
URL with the standard parameters, as HTTP parameters. The description 
with VOTABLE attributes is for the "service descriptor", as defined in 
DataLink spec, which is indeed a VOTABLE, and can help clients to create 
their interfaces on the fly.
An exemple section is surely needed. Moreover, we plan to have an IVOA 
implementation note for combining ObstAP or SIAV2, DataLink and SODA in 
the general perspective of "Data cube discovery, description and access"

Cheers
François
>
> 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/