[OSM-dev] all things to all people

Lambertus osm at na1400.info
Thu Apr 24 08:30:10 BST 2008


Brett Henderson wrote:
> 
> On Wed, Apr 23, 2008 at 7:54 AM, Frederik Ramm <frederik at remote.org 
> <mailto:frederik at remote.org>> wrote:
> 
>     Hi,
> 
>      >    Since the minute-diff was introduced OSMXAPI has been running, on
>      >    average, about 6 minutes behind the main database.
> 
>     Sigh, this project is too large already for one person to keep the
>     overview. Minute diffs you say. Hadn't heard of them until now, thanks
>     ;-)
> 
>  
> I really should do some more advertising, this has come up a few times 
> now :-)
> 
> I've also created tasks for populating a PostGIS "simple" schema which 
> is useful for maintaining a local replica of OSM data.  Latest SVN 
> osmosis has tasks for merging changesets into it so you could in theory 
> have a PostGIS database kept within 6 minutes of the main API.  It 
> should be very efficient at serving bounding boxes although only 
> real-world testing will confirm this.  There's still a few TODOs in 
> terms of keeping a database in sync that only stores a subset of the 
> planet, at the moment I can only apply whole planet diffs.
>  
Oh, that would be very useful for e.g. the Garmin map makers like myself.

I extract bboxes from a fresh planet file every week now and realise 
that I'm downloading most of the data every week again and that the map 
making process is delayed by the need to fetch 4 GB of data first. Being 
able to keep a PostGIS database up to date with small updates and 
efficiently (hopefully!) extract bboxes would be very welcome!

It would be of benefit for the NL tileserver that runs of a  PostGIS 
database as well, I think. Hopefully the scheme used by Mapnik and your 
'simple' scheme does not differ too much...




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