Elements to add to TabularSkyService

[Ray Plante]

Hey Martin,

On Thu, 1 Jul 2004, Martin Hill wrote:
> All I want to add (for now!) is the optional elements:
> 
>     <xs:element name="ErrorColumn" type="xs:string"/>
> 
> and
> 
>     <xs:element name="UcdPlus" type="xs:string"/>

Could you include some documentation?  For example, what exactly is the 
value of ErrorColumn correspond to, the name of the referenced column?

Are you still convinced that "UcdPlus" is necessary?

> so that both can be filled in as we deploy datacenters *now*; we can always 
> transform the metadata documents later if we change our minds. However if I'm 
> going to have to persuade data owners to go through a few hundred columns I'd 
> like to fill out the metadata fields as completely as possible, rather than 
> leaving some bits out and having to go over the whole laborious process again 
> later when we finally get around to agreeing a set of comprehensive tags.

What you might do is start by convincing the providers to add it to a few 
targeted tables for prototyping purposes.  

> Perhaps the best thing to do is for Astrogrid to develop the 
> TabularSkyService type, since it appears that noone else is going to use 
> it anyway?  As I understand it, the only other people developing 
> SkyNodes are NVO, and they are not going to provide this metadata as a 
> document.  

That is not quite correct.  TabularSkyService is the base type for the 
ConeSearch and SimpleImageAccess as well.  Furthermore, the difference in 
opinion regarding table descriptions in the registry is not so much 
whether we should but whether it is required.  By making it optional, we 
can experiment.

Nevertheless, I welcome AstroGrid's prototyping in this area.  If you 
really wish to push things (e.g. add lots of new stuff), it might be best 
to handle this initially through your own local extensions.  I'm happy to 
recommend friendly ways of doing this.  

cheers,
Ray