Hi Ole, Am Donnerstag, 9. August 2012, 17:55:24 schrieb Ole Nielsen / osm: > First of all I actually approved the proposal but later realized that > having variable keys is less than ideal.
then *please* tell me the reason why you believe this is the case, because I haven't seen any compelling counter-argument so far. What I have seen from different people: - allows for an almost infinite number of keys: existing tagging shows that keys tend to cluster, e.g. maxspeed:(22:00-06:00) is in use 395 (!) times with 6 different values (putting this into perspective: meagre 4494 occurences of maxspeed:backward). Those clustering effects become even stronger with increased usage. - kills PostgreSQL database performance: when you preprocess your routing data, you have to do a linear scan over all tag hstores anyway. - difficult because of special chars: the only situation where this actually matters is when you search inside your editor – and in that case the ':' already requires you to quote your key, at least in JOSM - difficult to parse for computers: every programmer can tell you in a second that this is plain wrong - difficult to parse for humans: so far, everybody I talked to about this was able to grasp the meaning of maxspeed:(22:00-06:00) = 100 in a split second And – of course – my favourite: - un-OSM-y, don't like it Eckhart _______________________________________________ Tagging mailing list Tagging@openstreetmap.org http://lists.openstreetmap.org/listinfo/tagging
