[OSM-dev] osmtools first release
Hendrik Siedelmann
hendrik.siedelmann at googlemail.com
Sun Apr 27 16:40:15 BST 2008
Perhaps I should have mentioned that only nodes without tags are
completely ignored in the database. Nodes that contain tags will
remain in the database.
Also a point is saved as two 32bit unsigned integer, which means a id
takes as much space as a point. And two 32bit numbers can also be
interpreted as a singel 64bit Id.
Ok now I think i've flooded the list enough with mails.
2008/4/27 Hendrik Siedelmann <hendrik.siedelmann at googlemail.com>:
> 2008/4/27 Frederik Ramm <frederik at remote.org>:
>
> > > Instead ways directly consist of a
> > > number of points. This should speed up for example rendering to svg or
> > > routing by a huge amount.
> >
> > For routing, it is important to know whether two ways meet at a
> > junction or whether they just pass over or under each other. This
> > topology requirement is solved by our nodes. If you drop nodes ("the
> > completely redundand id<->point assignment is removed"), how do you
> > suggest a routing engine should build its routing graph then?
>
> Nodes can still be identified by their lat/lon coordinates. As nodes
> are not duplicated in the database this is possible. And routing still
> needs to find which ways reference a node, so routing from one way to
> another is still complicated. On the other hand checking if another
> way uses the same points is fast on a spatial database (I will at some
> time provide funktions provide routing)
>
More information about the dev
mailing list