datatypes (effects all 3 WDs to some extent)

[CresitelloDittmar, Mark]

All,

as an FYI:
For the Spectral/ImageDM work that I'm doing, I have been formalizing the
set of datatypes that are used.
The foundation for these is coming from working with VODML and include the
'primitives' (real, integer, boolean, etc)
and a set of "Quanity" types (which include units/ucds).  For each 'model',
I am creating additional datatypes specific
to that model ( e.g. "Contact" for Spectal, and enumerations ).  Just
recently, I defined an "Interval" datatype,
which I want to use in place of the STC coordInterval object set.

So, I fully agree.  I'm finding it difficult to re-use models partially
because the datatype definitions are
either vague, or incompatible.  It would be nice to have a set of datatypes
defined which we can build from.

Mark




On Wed, Mar 19, 2014 at 4:02 PM, Patrick Dowler <
patrick.dowler at nrc-cnrc.gc.ca> wrote:

>
>   Really,  we are passing in a numeric interval as the value of the query
> parameter, so add that to the list of implicit datatypes. In future, one
> might think about describing the spectral or time coverage using such a
> numeric interval instead of two scalar values, just like we describe the
> spatial footprint using geometry.
>
>
So, we have a mismatch between the datatypes we are trying to use and our
> ability to describe them. How far back does that go? Well, ADQL-2.0 also
> uses datatypes but doesn't define them... And VOTable defines some datatype
> descriptions but not these ones (xtype hack noted). I would say that
> current DMs don't define these things as datatypes per se: they do have
> structures that accomplish the same sorts of things within the domain but
> that is not the same as defining datatypes.
>
> *** What to do?
>
> Ideally, we would have a document that defines datatypes and serialised
> values. Then ADQL-2.x would refer to that document, VOTable-1.x (x>3) would
> need to support serialisation of values of those datatypes. TAP-1.x would
> not have to say as much about datatypes as it does now, so it would get
> stripped down a bit. Other DAL and DM documents could use the datatypes by
> reference to a definitive document.
>
>
>
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