[OSM-dev] osm2pgsql deltas

[Steve Hill]

On Mon, 18 Jan 2010, John Smith wrote:

> Which is why you keep your system 2-5 minutes behind the DB system and
> you don't have to catch up ;)

Feel free to buy me a server that is capable of doing this. :)

My server isn't exactly underpowered, but:

1. From a blank database, it takes several days to import the planet file 
in slim mode.  This means that even if I start importing the planet file 
the moment it is available, by the time it has finished my server will 
have several days of deltas to catch up with.

2. At times, there is enough new data in the deltas to cause my server to 
fall behind.  My existing system automatically switched to using hourly or 
daily deltas as appropriate when it has got far enough behind for them to 
make sense - this helps it catch up quicker.

3. Any outage is going to end up causing me to have to play "catch up" 
again anyway, so the faster this can be done the better.

Most of this is down to I/O load, and there is only so much that can be 
done to boost database performance.

-- 

  - Steve
    xmpp:steve at nexusuk.org   sip:steve at nexusuk.org   http://www.nexusuk.org/

      Servatis a periculum, servatis a maleficum - Whisper, Evanescence