[vodml] Attribute multiplicity

[Arnold Rots]

I want to repeat a suggestion that I made earlier. even though I know
that it was pooh-poohed by Gerard. But I still think it could ameliorate
teh concerns and it did not really receive serious consideration.

Right now (i.e., before the message Mark just posted) we have the
following options for attribute multiplicity:
n
0,n
where n is a positive integer.
Mark's message would also allow:
0..n
0..*
What I had suggested is to restrict this somewhat by requiring that
any indeterminate (that is, in the model) attribute multiplicity be
explicitly stated through a non-negative attribute, replacing
0..n and 0..* simply by:
n
as is currently allowed, but with n being either a literal or a
non-negative integer attribute, like
n:nonnegativeInteger
a:real{multiplicity=n}

So, the question is: would this help in preventing bad modeling?
I thought it might, since it makes the model less indeterminate.

Cheers,

  - Arnold


-------------------------------------------------------------------------------------------------------------
Arnold H. Rots                                          Chandra X-ray
Science Center
Smithsonian Astrophysical Observatory                   tel:  +1 617 496
7701
60 Garden Street, MS 67                                      fax:  +1 617
495 7356
Cambridge, MA 02138
arots at cfa.harvard.edu
USA
http://hea-www.harvard.edu/~arots/
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On Fri, Feb 19, 2016 at 3:47 PM, CresitelloDittmar, Mark <
mdittmar at cfa.harvard.edu> wrote:

> All,
>
> Update on this topic:
>   In a recent focus-meeting in Baltimore, this topic was heavily discussed
> and explored.
>
>
> The primary reason for the restriction is that it typically will catch an
> instance of 'bad' modeling,
> where a concept has been denormalized to a simple type.  It is not that
> there is something
> inherently wrong about the open multiplicity.  It was also noted, that the
> same 'bad' modeling
> is not caught when the multiplicity is a fixed length.
>
> However, there seems to be areas where it MAY be useful to have such
> multiplicity.
> In reviewing the concequences of needing to allow this condition later, it
> seems that
> it may be large.. effecting vo-dml spec, and possibly votable spec as
> well.
>
> In the end, it was agreed that vo-dml should be modified to allow the open
> multiplicity on attribute types.
> It was agreed that the document should be be very clear about the modeling
> concern and that the
> condition should be strongly discouraged.  As a procedural matter,
> occurances should be discussed
> within the group for alternative representations.
>
> Actions:
>   GL - update the specification accordingly.
>          update xslt scripts to issue WARNING when the condition is
> detected as a reminder to
>          review the modeling.
>
> Mark
>
>
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