query to return redshift DB size

redshift_db_size.sql

select sum(mbytes)/1024, database from (
    select trim(pgdb.datname) as Database,
    trim(a.name) as Table, b.mbytes
  from stv_tbl_perm a
  join pg_database as pgdb on pgdb.oid = a.db_id
  join (select tbl, count(*) as mbytes
  from stv_blocklist group by tbl) b on a.id=b.tbl
    where a.slice=0
  order by db_id, name)
  group by database;