[Routing] generalized routing format - pre-computation

[Sascha Silbe]

On Sun, Oct 19, 2008 at 01:05:02AM +0200, Lambertus wrote:

>> Does gosmore check place=... areas to determine whether a way is 
>> inside a built-up area to adjust the speed accordingly? In that case 
>> I'll have to dig into the Gosmore source again to see how Nic got it 
>> this fast. :)
> No, afaik Gosmore does not do that.
OK. That was what I asked about - those checks are quite expensive, so 
I'm looking for ideas how to speed them up.

> And if appropriate maxspeeds are tagged then it won't need to.
I don't think we agree there - IMO default maximum speeds (e.g. 50km/h 
inside cities) shouldn't be explicitly tagged. That's a different 
discussion, though, let's have it on talk if at all. I'll just mention 
that setting the default maximum speed for _cars_ as maxspeed=... means 
entering wrong data for the other vehicle types: In Germany speed limit 
signs within a built-up area may actually _raise_ the limit above 
defaults for _all_ vehicle types.

> Perhaps you use this during namefinder lookups?
It's a simple yes/no check, no names.

> Gosmore doesn't use much ram while parsing the planet data so I'm 
> pretty sure it will scale linear whatever the amount of data.
The amount of RAM used for temporary data is quite low, but the whole 
database is mmap()ed into memory. I thought Gosmore does the same?!

CU Sascha

-- 
http://sascha.silbe.org/
http://www.infra-silbe.de/
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