On Mon, Jan 12, 2009 at 10:57:24AM +0100, Erik Johansson wrote:
I remember David Earl mentioning a scheduled database rebuild. Perhaps its currently running. Otherwise, I'd really like to know the reasons (so I can test my own implementation accordingly).I have two questions; why is gazetteer.openstreetmap.org so slow at 20-50 seconds per request,
and if anyone has code for faster variants of name finders? Speed is essential..
I have done an alternative, but suspended its development becausea) the current Namefinder was sufficiently fast when I tried to compare them => don't know under which conditions it's slow, so I cannot test whether my implementation really is faster in these cases; and
b) because I haven't had enough time to finish it.The core (written in C/C++) is almost finished (only some minor changes for name canonicalization needed). What's really missing is the "front-end" part, i.e. the web server and search plan generation. A Python module implementing the protocol between Core and Frontend is included, so someone else could start implementing it right away. :)
To give some funny, unscientific numbers:General conditions: planet-080813.osm.gz, Athlon 64 BE-2300 dual-core 1.9Ghz, 4GB DDR2-800, Limit 100 ways + 100 nodes per step
Data base size: ~8GB
import time: 206 minutes
startup time: 41 seconds
RAM usage after startup (-> names and hash tables): 501MB
name search ("Provenceweg", exact): 0.001117s
loc search (48.51 9.07 48.52 9.08): 0.061777s
exact name + loc: 0.001331s
loc + exact name: 0.005612s
name search ("Provenceweg", regex): 2.582227s
loc + regex: 0.232248s
exact name + loc (whole world): 2.263841s
loc (whole world): 0.069157s
Name search ("Provenceweg", substring): 0.600431s
Unfair comparison with current namefinder (my code: local, no frontend;
gazetteer: remote; with caching, i.e. first result is discarded):
old new
Beethovenweg 0.681s 0.008970s
random string (=> 0 results) 0.310s 0.000352s
I've released my code under GPLv2 in my arch repository [1] as
osmsearch--devel--0.1 (haven't had an idea for a better name yet,
sorry).
You'll need some data files [2-4] as well.Instructions for fetching the source (assuming the GNU arch client "tla" is installed):
1. tla register-archive http://sascha.silbe.org/arch/[email protected] 2. tla get [email protected]/osmsearch--devel--0.1 osmsearch--devel--0.1
This will put the source into a newly-created directory called "osmsearch--devel--0.1".
[1] http://sascha.silbe.org/arch/[email protected] [2] http://sascha.silbe.org/tmp/osmsearch.conf [3] http://sascha.silbe.org/tmp/nodesDisplay.rules [4] http://sascha.silbe.org/tmp/waysDisplay.rules CU Sascha -- http://sascha.silbe.org/ http://www.infra-silbe.de/
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