[osmosis-dev] Osmosis use case

[Walschlager, Gerard]

Hi Frederik,

I appreciate your quick response!  I am not surprised by your answer.  Any idea on how much disk space would be required by a PostGIS database that would hold the entire planet.osm file data?

I'm not sure what the "simple schema" is.  I assume that is different than resolution #2 that you indicated in your reply?  I assume that in answer #2, there is a standard schema that Mapnik assumes must be in place in the database it will query and that schema is different than the "simple schema" specified in answer #1?

Thanks,
Gerard 

-----Original Message-----
From: Frederik Ramm [mailto:frederik at remote.org] 
Sent: Friday, March 26, 2010 5:48 AM
To: Walschlager, Gerard
Cc: osmosis-dev at openstreetmap.org
Subject: Re: [osmosis-dev] Osmosis use case

Hi,

Walschlager, Gerard wrote:
> My question concerns how to do this.  One option would be to use Osmosis 
> to generate a local database containing the XML from "planet.osm" such 
> that it could be queried in a variety of ways quickly.  However, for my 
> simplistic use case of simply extracting a bounding box worth of XML, 
> would Osmosis perform this operation quick enough such that a user of my 
> application could specify the bounding box, Osmosis would extract that 
> bounding box directly from the "planet.osm" file

No. That requires parsing the whole file and I have yet to encounter a 
machine that can do this under 1 hour.

I can think of two ways how you could handle your problem.

1. Import full planet into a PostGIS database using Osmosis' "Simple 
Schema". Then use the -dbb task to extract data from that. I have not 
used that but the data extraction should run quickly. The process the 
extracted data with a renderer of your choice to yield an image.

2. Import full planet into a PostGIS database using osm2pgsql. Then use 
Mapnik directly to render an image for the area of interest.

If all you need is a PNG map image or so, the second option is 
recommended. The first path is less traveled.

Bye
Frederik