[Openstreetmap] graph reduction (was: more distributed ideas)

[Immanuel Scholz]

Hi,

> But I have been thinking can you reduce it by doing this:
> 1. Transform  all nodes in the bbox to x/y of the current tile
> 2. pick a (random/or someother way) point
> 3. simplify all nodes that are in a 3x3 square around this point to a new
> node
> 5. connect all the old segments that linked to the deleted nodes to this
> node.
> 6. go to 2

This means, all nodes and all line segments in the given area need to be
processed.

If the assumption is true, that bottleneck for delivering street
information is the CPU power (or I/O capabilities) of the server and not
the bandwidth, this is currently contra-productive.

If objects are tagged after importness, the amount of data to be processed
(and transfered) can be reduced at SQL level.


Maybe your algorithm can be used to auto-tag the whole dataset to get a
quick start.

Ciao, Imi.