[Openstreetmap-dev] Performance measurment and CSV
immanuel.scholz at gmx.de
Sat Dec 31 21:30:32 GMT 2005
while I was bored waiting for the big party to start, I did some
performance measurements of the code we currently use to retrieve map
For this, I wrote a small ruby script to generate a dataset for the test
You will find it in sql/make-random-data.rb
Using this data, I test the speed of the various steps within map.rb. This
turned out (the numbers are in seconds):
overall (in map.rb): 22.598376
overall (measured at client including transfer): 23.004521
So this means, that almost the whole time (78%) is spent in converting the
data to xml output. The time to transfer the data is practically
irrelevant (2%). Note, that I even did not use the gzipped feature.
WHAT A SURPRISE! (Really, I didn't forecast this.. :-| )
So its time to either use another XML library, use another platform (no
ruby :-( ) or reactivate our discussion about CSV.
For the CSV thing: We already have an object modell that supports a rather
linear expression of the data, so defining an transport mechanism should
not be that hard. And btw: Ruby support CSV in one of its standard
Any volunteer for a transport format specification? (I'll do it, if you
don't want ;)
Any other comments?
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