[OSM-dev] Table/Index Access (for SSD)

[Lynn W. Deffenbaugh (Mr)]

On 6/18/2012 3:31 PM, Frederik Ramm wrote:
> Use
>
> select pg_size_pretty(pg_total_relation_size('tablename'));
>
> to find out how much your tables need. If your database is nothing 
> fancy then planet_osm_{point,line,roads,polygon} will total about 90 
> GB including their indexes (which pg_total_relation_size takes into 
> account). These are the *only* tables used for rendering so if you 
> migrate these onto SSD, your rendering will be almost as fast as on a 
> 100% SSD system, with only small improvements to the update process.

Very good.  That's exactly what I was looking for.  In my DB, I get:

planet_osm_point: 4369MB
planet_osm_line: 41GB
planet_osm_roads: 8530MB
planet_osm_polygon: 34GB

for a total of just under 88GB so a 120GB SSD should do the job.  Now, 
to see if I can figure out how to split up the DB to assign different 
tables to different places....

And I gather that the remaining planet_osm_* tables are the "slim" 
support to allow for diff-based updating?

planet_osm_nodes: 97GB
planet_osm_rels: 4261MB
planet_osm_ways: 109GB

Lynn (D) - KJ4ERJ