show occupied space in a postgresql database

db-size.pg.sql

create view v_sizeof_dbs as
select datname dbname
  ,pg_size_pretty(pg_database_size(datname)) hsize 
from pg_database 
order by pg_database_size(datname) desc;

create view v_sizeof_tables as 
SELECT table_catalog,table_schema,table_name
  ,pg_size_pretty(pg_table_size(table_schema||'.'||table_name)) table_hsize
FROM information_schema.tables
where not table_schema in ('pg_catalog','information_schema') 
and table_type like '%TABLE%'
ORDER BY (pg_table_size(table_schema||'.'||table_name))  desc;