MIVOT: fully qualified attribute names

[Markus Demleitner]

Dear DM,

I have just added a few points to the MIVOT RFC
<https://wiki.ivoa.net/twiki/bin/view/IVOA/DataAnnotation> both as
WG chair (mostly relating to the proof of implementation) and as
myself.  From these comments as myself, there is one that I think
should be discussed more widely, which is why I'm taking it here:

I admit I have never been particularly fond of fully qualified role
names ('dmrole="ivoa:Quantity.val"') -- I've always considered them a
lot of letters for very little gain.

But now that I have tried to implement MIVOT annotation in DaCHS, I
have found that with these qualified names, I have to parse (and
understand) VO-DML files and then follow inheritance hierarchies --
just to infer these fully qualified attribute names. That's about an
order of magnitude more work than if I can just write 'dmrole="val"'.

Note that the type an attribute sits on is already given by the
dmtype of the embedding element, except that that's the actual type,
not the type that defines the attribute, so we would not be losing a
lot.

Given that: is there a really strong reason to have these qualified
role names?

While I was trying to research how these role names are supposed to
work in the first place, I noticed that the spec apparently does not
say anything about how these role names are to be derived.  So, if
this discussion actually results in a strong reason to keep them
fully qualified, I'd say MIVOT needs some normative language on how
to form these names.

          -- Markus