Hi Ilario,
I agree with you, thanks for structuring the discussion :)
On Wed, May 23, 2012 at 12:59 PM, Ilario Valdelli <valdelli(a)gmail.com> wrote:
The structure of the database is not an original
research but it is part of
the "infrastructure". The local identifiers cannot be primary key because
there is the problem of redundancy (mainly if we have a unique repository
for all countries), so to have a progress we have to define our own *primary
key* and connect it with the local identifiers in a way that can assure a
continuity and a long life of the new structure of the list of the
monuments.
I would add to that one additional requirement: The IDs created by and
for the database system should not show up on Wikipedia or Commons. A
list on Wikipedia should always contain and display the actual local
identifier as it is the case in the countries with just one numbering
system. That's what I consider the "OR issue" that we need to avoid
and which I tried to explain (poorly).
The use of an identifier for municipality is not a
good candidate for a
primary key because in some countries the municipalities may be aggregated
or may be split year by year. Probably an identifier connected with the
geographical coordinates may be a better candidate... but the real question
is that the identifier is a good point to be discussed and can become urgent
in the near future.
The connection with the municipality key has the advantage that it
reflects the structure of the lists: If every
municipality/county/district/state/nation assigns their own IDs, we
should just add prefixes to make them unique. (In fact, for most
german areas it's not the municipality but rather the district or
state level, so changes will be very rare.)
It also avoids creation of unnecessarily long and complicated IDs: If
a state keeps unique numbers, you just add the state identifier and
don't worry about location or municipality.
But that's just my point of view :-)
Kilian