[OSM-dev] osm2pgsql slow on update import

[Markus Wagner]

Hey everybody,

I hope this list suits the problem I'm trying to solve - searching the  
lists, forums, former posts, etc. didn't help.

I followed (roughly) this  
http://wiki.openstreetmap.org/wiki/DE:HowTo_minutely_hstore
guide to setup a PostGIS server; did a full planet import (took 16.x  
days) and now I want to catch up by importing the diffs as described  
there. Problem is, that a 5min fragment takes 7-11 minutes. (The same  
factor applies to imports of an hour, half day, etc.)

How can I investigate what the bottleneck is? So far, I can see, that  
there is a lot of I/O going on and not much CPU usage. The diff import  
is stuck upon prompting "Going over pending relations","processing  
relation (...)".

Some specs of my setup:
-Debian 64Bit
-PostgreSQL 9.0.3, PostGIS 1.5.2; having its own physical drive with XFS
-Intel(R) Core(TM)2 Quad CPU Q9505  @ 2.83GHz
-8 GB physical RAM
-The initial (and diff) imports have been using the default.style and  
keeping keeping coastlines
-a GIN Index has been created, turning its fastupdate option to off  
didn't help (rather, it even prolonged the append run)

Any pointers, tipps are welcome!

Thank you,
   Markus
-- 
Markus Wagner
markus at mwagner.info