::fixture-ready::
$ df -h /var/lib/postgresql
Filesystem      Size  Used Avail Use% Mounted on
/dev/vda1        40G   27G   11G  72% /var/lib/postgresql
::exit-code::0
$ psql -X -c "select datname, pg_size_pretty(pg_database_size(datname)) as size from pg_database order by pg_database_size(datname) desc;"
 datname  |  size
----------+--------
 app_prod | 384 MB
 app_test | 42 MB
 postgres | 11 MB
(3 rows)
::exit-code::0
$ psql -X -c "select datname from pg_database order by datname;"
 datname
----------
 app_prod
 app_test
 postgres
(3 rows)
::exit-code::0