Re: database size much bigger than tablespaces on filesystem

>>>> I check te database size like this:
>>>> select pg_size_pretty(pg_database_size('database'))
>>>> 595 GB

>>> You should also check the space held in $PGDATA/base.

>> I did. It is only 320 MB.

>Bizarre.  Try breaking the results down table-by-table to see if you can
>find where the discrepancy is.

>                       regards, tom lane

It gets stranger. I try this:

select 
  tablename
, pg_relation_size(tablename) 
, pg_size_pretty(pg_relation_size(tablename) ) as relsize
, pg_size_pretty(pg_total_relation_size(tablename) ) as disksize
, pg_total_relation_size(tablename)
from pg_tables where schemaname <> 'information_schema'
order by 2 desc

And all the tables report a 'disksize' larger than the 'relsize', which seems natural. The biggest table (relsize) is
around5 GB. 
 
I wonder where the rest of the size comes from?

-Rob