select pg_size_pretty(pg_total_relation_size('radius_db.radacct'));
Relation w/ inheritance:
select pg_size_pretty(sum(pg_total_relation_size(inhrelid))::bigint + pg_total_relation_size('ods_db.radius_cdr_pdp')) from pg_inherits where inhparent='ods_db.radius_cdr_pdp'::regclass;
