List all databases in Postgresql and their sizes and ordering by size descending

List all databases and size

psql -c "select p1.datname as DB_Name, pg_size_pretty(pg_database_size(p1.datname)) as DB_Size from pg_database p1 order by pg_database_size(p1.datname) desc;"


List size of a particular database.

select pg_database_size('databaseName');