[Tagging] is tourism a good category for everything cultural?
info at 4x4falcon.com
Tue Aug 24 09:29:13 BST 2010
On Tue, 24 Aug 2010 10:03:42 +0200
Ulf Lamping <ulf.lamping at googlemail.com> wrote:
> Am 24.08.2010 09:36, schrieb Ross Scanlon:
> >> Well, I will take a change to 'troll' again about it. This discussion
> >> comes up again and again because we don't have:
> >> a) clear tagging guidelines (*not* rules)
> >> b) mechanism to replace tags
> > Agree totally.
> > This (b) would be easily recitified by normalising the database in regards to tags.
> So how do you easily: "normalise the mappers minds, renderers, editing
> software in regards to tags"?!?
> Over several years past now, I have seen this discussions come and go.
> When someone was actually doing something, it usually ended up in a mess
> of wiki, mappers, editors and renderers disagreeing how to tag
> something. A confusion causing a *lot* more harm than any good.
> It's simply a misconception, that just "cleaning up" the tag names will
> lead to an easier mapping experience.
> Regards, ULFL
You have no idea about normalising a database do you.
It has nothing to do with what you have above.
Rather than storing a tag as a key=value, you store it as a unique identifier.
The identifier is then referenced in another table in the database which will provide the key and value.
Lets take an example.
Currently in osm we have a road tagged with the following:
If the database was normalised then the following would occur.
The tagging table would have in it:
for a tag_id of 1000000
for a tag_id of 1000001
Now say that we decide that we no longer wish to call residential ways "residential" but a new name of "house streets".
To change the current database it would take a lot of effort but with a normalised database all we have to do is change the "value=residential" in the tagging database to "value=house_streets" and every way that was tagged residential is now tagged "house streets".
Tags like name would not have a tag_id as they are not unique.
The renderers would simply have to look in the tagging table to see what needs to be displayed.
More information about the Tagging