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

Frederik Ramm frederik at remote.org
Mon Jun 18 20:31:13 BST 2012


Hi,

On 18.06.2012 19:50, Lynn W. Deffenbaugh (Mr) wrote:
> My current DB is just under 300GB (yes, it needs a VACUUM), and I'm
> trying to figure out if 120GB or 240GB worth of SSD could be employed
> for selected tables to improve diff application as well as rendering
> performance, primarily the latter.

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.

Bye
Frederik

-- 
Frederik Ramm  ##  eMail frederik at remote.org  ##  N49°00'09" E008°23'33"



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