redshift-clusterSize

SELECT
  CAST(pg_database.datname AS VARCHAR),
  bytes
FROM
  (SELECT
     p.db_id,
     sum(b.blocknum * 1048576) AS bytes
   FROM pg_catalog.stv_tbl_perm p JOIN (SELECT
                                          bl.tbl,
                                          bl.slice,
                                          count(bl.blocknum) AS blocknum
                                        FROM pg_catalog.stv_blocklist bl
                                        GROUP BY bl.tbl, bl.slice) b ON b.tbl = p.id AND b.slice = p.slice
   GROUP BY p.db_id
  ) AS dbsizes
  JOIN pg_database
    ON dbsizes.db_id = pg_database.oid
ORDER BY bytes DESC;