[OSM-talk] OGL, OSM, NASA

[Raphaël Jacquot]

Immanuel Scholz wrote:
> Hi,
> 
> 
>>>What part is slow?
>>
>>guess he wasn't using libxml2's sax interface :D
> 
> 
> Yea.. my ruby script uses REXML (its sooooo easy ;-). and so it is slow.
> 
> But hey, you know, you don't HAVE to sit before you computer watching him
> all the time executing a script, right? ;-))))

that's correct, I'd better have it do the thing in a second so I can go 
back doing something productive :D

>>I'll attribute the slowness to
>>
>>1) insane SQL queries ( see
>>http://trac.openstreetmap.org/browser/ruby/api/wms/streets.pl#L52 for a
>>good example)
>>
>>2) not using a geometric-aware database engine (1 stems partly from this)
>>
>>3) from 2, not using proper indexes on the things that matter most,
>>specifically indexes that would greatly accelerate requests looking for
>>stuff that is within a 2D box
> 
> a) Observation: Predictions are usually wrong
> b) Conclusion: I predict that you are wrong.  :-D

well...

a) observation: I have done my homework prior to writing this mail.
b) conclusion: my working code is visible... go for it, point your josm 
to my osm api server, and attempt to download a map
(that's where you'll notice that the java xml implementation you're 
using sucks :D... to get a proof of that, do "time wget <blah>" ...)

no, scratch that, lemme do it for you (this is from my work machine, 
over the dsl link)

sxpert at raph-dell ~ $ time wget 
'http://www.navsys.org/api/0.3/map?bbox=5.6546745899872715,45.14032050966251,5.8370048596246535,45.23012105673176'
--14:55:30-- 
http://www.navsys.org/api/0.3/map?bbox=5.6546745899872715,45.14032050966251,5.8370048596246535,45.23012105673176
            => 
`map?bbox=5.6546745899872715,45.14032050966251,5.8370048596246535,45.23012105673176'
Resolving www.navsys.org... 82.228.185.17
Connecting to www.navsys.org|82.228.185.17|:80... connected.
HTTP request sent, awaiting response... 200 OK
Length: unspecified [text/plain]

     [                                                 <=> 
                                          ] 924,206       98.71K/s

14:55:46 (72.24 KB/s) - 
`map?bbox=5.6546745899872715,45.14032050966251,5.8370048596246535,45.23012105673176' 
saved [924206]


real    0m16.826s
user    0m0.004s
sys     0m0.036s

> No, fun aside. I made the very same assumption, then did a bit of
> benchmarking and found me completly wrong. This had such a surprising
> impact on me, that I did not tried to ever made any other predition about
> the current server code... ;-)
> 
> Ciao, Imi.