[OSM-talk] Fetch whole relation when parts of it are in bbox

Dave Stubbs osm.list at randomjunk.co.uk
Mon Nov 5 12:55:54 GMT 2007


> Something that may be nice is if the api could return ways whose
> bounding boxes intersect with the bounding box have downloaded, even if
> the way has no nodes inside the area. This would download any ring areas
> around the area you are looking at, and it would also download straight
> streets that crossed your area with no nodes in them.

That would require the API knowing the bbox for a particular way...
unfortunately it currently can't find this out without first finding
all the nodes for a particular way. You would have to maintain a bbox
for each way in the database to do this efficiently. This would cause
a number of problems with update efficiency as every node edit would
have to update the bbox's of any ways it is a member of, which would
require finding all the other nodes. I don't know how critical it is
that node update requests are handled quickly... it's possible there
may not be that many of them. And somebody may point out a more
intelligent way of handling this.

On a more "is this a good idea" point of view, you could load a
surprising amount of data for a simple small area request if you're in
an area with lots of longer curving roads, or lumpy coastline etc.
Depending on how large people have made the ways of course.




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