[OSM-dev] MySQL GIS extensions - some tipps

[Andreas Kalsch]

marcus.wolschon at googlemail.com schrieb:
> On Tue, 21 Jul 2009 13:53:20 +0200, Andreas Kalsch <andreaskalsch at gmx.de>
> wrote:
>   
>> Roland,
>>
>> Which MySQL branch have you used?
>> I use a sandboxed 5.1.35 source distribution for testing, which 
>> implements _full_ OpenGIS functionality - it works pretty accurate and 
>> for me fast enough.
>>     
>
>
> Well, what are you doing with it?
>
> Is is fast enough for interactive rendering
> slightly below a city-level? (Above that I am
> using simplified maps to scale up to rendering
> continents.)
>   
I don't render maps with it, so I don't know how it scales. But Mapnik 
will connect easier to Postgres/PostGIS. I will outsource rendering for 
my project.
> Can you decompose a POINT into lat+lon in an SQL-query?
> If not, how much space is wasted by having all coordinates
> twice?
>   
Yes. But I just put relevant features into the geo database - I save 
nodes and ways which have relevant tags, and relations as 
GeometryCollections and MultiPolygons. It makes no sense to put nodes 
and ways into the GIS table, which are just parts of ways/relations and 
do not play an own role. Result: 5 of 17.3 GB (for Europe) is for GIS 
data. I use the GIS table for analysis and re-computing. It pays off.