[OSM-talk] OGL, OSM, NASA

Immanuel Scholz immanuel.scholz at gmx.de
Tue Apr 25 13:48:25 BST 2006


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? ;-))))


> 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


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.






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