That's pretty much entirely a relation-as-category, though, isn't it? I'm wondering whether there'd be a case for a very small number of high-value (in terms of processing speed) relations to be created automatically, available to data consumers in the normal way through the API, but _not_ shown in editors? These relations really just make things more complicated.
Richard On Fri, Oct 19, 2012 at 10:57 AM, Matt Williams <li...@milliams.com> wrote: > On 19 October 2012 10:05, thomas van der veen <th.vanderv...@gmail.com> > wrote: > > I have used the terraced house plug in a few times and have found it very > > useful, but I don't quite understand the difference between addr:street > > (which is what I do at the moment) and adding a relation? > > > > Could you please explain this a bit more (and if possible in other > contexts > > then the postcode finder) > > Sure. All this addressing is based on the Karlsruhe Schema [1] which > was devised as a way of tagging streets by some Germans who wanted to > try out tagging a whole city. The original schema was a series of tags > you put on each house such as house number, post code etc. The way > they originally specified which street a house is on was by the > addr:street tag where they would put the name of the street in that > tag on each house. > During the process of this schema evolving and being used, some people > felt that this was redundant and so decided to start using relations > to group these houses together (along with the street). I have a > feeling this was in the early days of relations when many people > weren't sure how to use them and so adoption of this method was slow. > > So, for adding in data as a mapper, it a difference between adding an > 'addr:street' tag to every house in the street or selecting all the > houses and roads in the street and adding them to a single relation > (with the correct roles). For many people, creating a relation like > this is seen as unnecessarily burdensome when for them, the > addr:street method describes what they mean just fine. > > For data consumers (Nominatim, postcode finder, routers etc.) I would > argue that it's conceptually simpler to use the relation method since > it's explicit about that's in the street and what's not. With the > addr:street method, the programmer has to, upon finding a node with an > addr:street tag on it, search 'nearby' in the database. This means > that they must have a georeferenced database set up and these querys > are not as fast as simply node/way lookups. Also, to assemble a full > street (from many ways and houses) would require an iterative building > process. For me as a data consumer, the advantage of the > associatedStreet relation comes from explicitness and speed. > > What I think we need (and what I've started to look at) is a plugin > for JOSM (or built-in for Potlatch) which allows you to simply select > the houses and the street, press a button and the relation is > magically created. If some of the selected items are already in a > relation then the rest of the items are added to it. > > Some of this is just my (biased) opinion so feel free to do whatever > works best for you (of course, you could always do both). For > information on exactly how I tag addresses with relations, see [2] > (which I'd like to announce is up and running again). > > Cheers, > Matt > > [1] > https://wiki.openstreetmap.org/wiki/Proposed_features/House_numbers/Karlsruhe_Schema > [2] http://milliams.dev.openstreetmap.org/postcodefinder/tagging/ > > _______________________________________________ > Talk-GB mailing list > Talk-GB@openstreetmap.org > http://lists.openstreetmap.org/listinfo/talk-gb >
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