text: select
  df.tablespace_name as tablespace,
  (df.totalspace - tu.totalfreespace) as usedMb,
  totalfreespace as freeMb,
  df.totalspace as totalMb
  from
  (select
      tablespace_name,
      round(sum(bytes) / (1024 * 1024)) totalspace
      from {{ dba_data_files }}
      group by tablespace_name) df
  left join
  (select
      round(sum(bytes) / (1024 * 1024)) totalfreespace,
      tablespace_name
      from {{ dba_free_space }}
      group by tablespace_name) tu
  on df.tablespace_name = tu.tablespace_name
  