[OSM-talk] osm2pgsql hstore (was: Wind turbines no longer rendered on mapnik layer)

[Stephan Knauss]

Komяpa writes: 

>> - is a database generated by osm2pgsql with an hstore expected to perform
>> similarly to one without?
> 
> It performs at the same speed for me. 
> 
> Of course you're not supposed to use hstore for every tag, but just
> for those on highest zoom levels, where spatial indexes are used
> mostly, not indexes for other columns.

if you are using Postgres 9.1 you are advised to update to 9.1.2. There was 
a bug introduced that prevented index usage. For example testing for a tag 
like
SELECT * from table WHERE hstore ? tag
did not use an index and could make a query horribly slow. We experienced 
this on Toolserver. 


Stephan