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Re: [overpass] Query by quad tile key


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  • From: Roland Olbricht <roland.olbricht@gmx.de>
  • To: overpass@listes.openstreetmap.fr, overpass@osm101.openstreetmap.fr
  • Subject: Re: [overpass] Query by quad tile key
  • Date: Thu, 16 Feb 2017 07:05:52 +0100

Good morning,

Is there a way to query by just providing a quad tile key?
Further options are not required. Just this.
For background: I need all data and have rather complex processing in mind.
Result will be tile based anyway and data structure seems already very
suitable for that.

Not really. The problem is that the ways are in overlapping index structures. Hence, a strict quad tile based approach would miss those ways that cross a tile's border.

What works now is to have bbox limitations
from 0.0000000 + n * 0.0065536 to 0.0065535 + n * 0.0065536
This matches exactly the tile boundaries and assures that each way is in at least one tile.

What also works is to use "out qt" (or "out meta qt"). This orders ways by quadtile and is guaranteed to produce each way exactly once.

To have a quad tile criterion I would need to know what should happen to boundary crossing ways. If you just need to get data in chunks then I would then I could make a filter "chunk" or so that gets a integer, without a guarantee that ways are spatially ordered but with a guarantee that each way is contained in exactly one chunk. The chunks will be of very different sizes.

Regards,
Roland




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