[Tagging] admin_level on nodes: wiki vs practice

Ilya Zverev zverik at textual.ru
Tue May 13 12:20:02 UTC 2014


Dear community, WTF?

admin_level on place nodes surely duplicates admin_level tag value
from one of relations which contain that node, but is that a bad
thing?

Did you try to calculate admin_level for a place in osm2pgsql
database? I've spent two hours now trying to construct and optimize an
SQL query for that, and seeing it takes at least 20 seconds for a
tile, I'd prefer having admin_level tag on places.

I know data users' problems are not mappers' problems, but why this
rare redundancy is being addressed instead of other, like foot=yes
with sidewalk=* (you can find thousand of other redundancies with
taginfo)? Why did you after just two days of discussion started to
remove this tags from nodes as important as GB's capital?

Please explain why admin_level on place nodes harms the database, or
refrain from removing it. Thanks.

IZ

> I've added a note to the wiki to avoid future confusion:
> http://wiki.openstreetmap.org/w/index.php?title=Tag%3Aboundary%3Dadministrative&diff=1037547&oldid=1000731

> On Mon, May 12, 2014 at 6:30 AM, Martin Koppenhoefer
> <dieterdreist at gmail.com> wrote:
>>
>> 2014-05-11 3:50 GMT+02:00 Nelson A. de Oliveira <naoliv at gmail.com>:
>>
>>> Using "admin_level" outside (or without) a "boundary=administrative"
>>> relation will be as wrong/incomplete as using "service" without a
>>> "highway=service", "railway" or "waterway"; or using "crossing_ref"
>>> without "crossing", for example.
>>
>> +1
>> I'd also see it like this. Use the role admin_centre in administrative
>> relations to include the central place, and/or add a
>> capital=<admin_level-number> on the place object to store its administrative
>> importance conveniently (no need to evaluate administrative relations or to
>> inherit importance from a relation).


IZ




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