[Tagging] [OSM-talk] emergency=*

[Brian Quinion]

On Fri, Jul 30, 2010 at 2:42 AM, Ross Scanlon <info at 4x4falcon.com> wrote:
>> Better yet - just don't change it.  This sort of change just isn't
>> worth the pain and hundreds of developer hours that could be better
>> spent on moving the project forward.  Yes - this sort of change might
>> make the tag heirachy prettier - but not enough to justify the work.
>
> Garbage.
>
> It's not hundred of hours of developer work to change this.
>
> If the renderer programming is up to scratch then it should be able to automatically accept changes like this.
>
> One of the programs I have done some development on has this built in.

Well done.  Pretty much none of the others do.  I look forward to your
patches :)

Mapnik for instance has manual rules - they will need to be changed.
Worse than that osm2pgsql (the import tool) only imports certain keys
so implementing emergency=* requires a complete reimport of the
database - about 30 hours even on very good hardware.  Then the
changes need to be tested and deployed.  I can get to 3 or 4 hours of
actual developed work without even trying.

Now times that by the number of applications.  For applications that
are deployed to the desktop or mobiles the situation is even worse -
it might not be possible to release a new version of the time being,
the change might have to wait for the next update cycle and then all
the users have to actually get round to updating.  Or maybe they have
to code in some sort of hack to change the new tag back to the old tag
for compatibility.

And what about multi-lingual support?  A lot of apps are in multiple
languages, they might well need to go back to their translators and
check that the new tagging doesn't result in a subtle change in
meaning.

But all this is the tip of the iceberg - you are missing the time it
takes to monitor the tagging list (most developers will not even be on
it), to find out which changes are important and to work out if things
are exactly equivalent or if there is a change of meaning.

I think hundreds was a fairly reasonable number.

--
 Brian