ObsCore and extensions

[Markus Demleitner]

Dear Colleagues,

On Fri, Jan 17, 2025 at 02:48:19PM +0100, BONNAREL FRANCOIS gmail via dm wrote:
> > t_exp_min
> > t_exp_max
> It could be useful for time series outside the radio domain,  right. It's in
> the proposal for time extension too. I am  not sure if it's useful outside
> time series. I let Mireille and other Time extension authors comment on this

Ah, hm... this point made me think.  What happens if the same column
is present in multiple extensions?  I frankly would have hoped that
we can avoid that and carefully design the different extensions such
that only concepts specific to the the extension will be part of it.

Realistically, this will not be possible; people interested in an
extension will in general want to be able to do with one extension or
two at the max, and they in particular will not want to wait for
updates of other extensions, let alone Obscore itself.

The question is what to do then.  I see two possible ways out:

(a) use different column names.  But sure, it would suck if the upper
limit of exposure times of the artifacts within a data product (say)
had different names in radio, time domain, and high energy,
respectively.

(b) make it a strict validation requirement that the values in
different extensions compare exactly equal (which may not be an easy
feat for floating point numbers).  If we do that, our NATURAL JOIN
recipe for pulling in the extension will automatically do the right
thing.

Opinions?  Alternatives?

         -- Markus