To get the size of MySQL DB :

SELECT table_schema “production_db“, sum( data_length + index_length ) / 1024 / 1024 “Data Base Size in MB“, sum( data_free )/ 1024 / 1024 “Free Space in MB“ FROM information_schema.TABLES GROUP BY table_schema;

To get the size of PostgreSQL DB

select pg_database_size ( 'databaseName' );

To get size of accessible DB on PostgreSQL DB’s :