Jon Burgess schreef: > On Thu, 2008-05-29 at 16:51 +0200, Stefan de Konink wrote: >> Maybe this is discussed before, but I want to know what the general >> opinion is about it. >> >> I wonder if we can skip a table of ways, and instead make it a relation. >> And it would look as: >> >> <relation id="77" visible="true" timestamp="2006-03-14T10:07:23+00:00" >> user="fred"> >> <member type="relation" ref="343" role="from" /> >> <member type="node" ref="911" role="at" /> >> <member type="relation" ref="227" role="to" /> >> <tag k="type" v="way"/> >> </relation> >> >> Is there a reason not to implement it this way? > > I'm not sure I understand, but I think you are proposing that ways be > implemented as a type of relation. Two problems with this:- > 1) The list of nodes in a way is ordered. The members of a relation are > not ordered.
I have implemented an index for relations too. > 2) The relation IDs overlap with the way IDs. You would probably need to > renumber either all the ways or relations. True, but if that is the biggest problem... > In general though, do you really want to "optimise" the data by > converting the 20M concisely defined ways by making them look more like > the 11k generic relations in the DB[1]. This surely going to expand the > storage and processing overhead for the ways. That sounds wrong to me. I'll benchmark both solutions. Stefan _______________________________________________ dev mailing list [email protected] http://lists.openstreetmap.org/cgi-bin/mailman/listinfo/dev
