Get Database Schema and Table Sizes (PostgreSQL)
Get Database size
SELECT pg_size_pretty(pg_database_size('db_name_here')) As fulldbsize;
Get size of all tables in a schema
select pg_size_pretty(CAST((SELECT
SUM(pg_total_relation_size(table_schema || '.' || table_name) )
FROM information_schema.tables
WHERE table_schema = 'schema_name_here') As bigint) ) As tables_schema_size;
Get sizes of a table
Full_size = Size of table, its toasted tables and indexes
Table_only = Size of the table only
SELECT pg_size_pretty(pg_total_relation_size('table_name_here')) as Full_size, pg_size_pretty(pg_relation_size('table_name_here')) as Table_only;