Largest tables

SELECT n.nspname || '.' || c.relname AS table_name,
       pg_size_pretty(pg_total_relation_size(c.oid)) AS total_size,
       pg_total_relation_size(c.oid) AS total_bytes,
       pg_size_pretty(pg_relation_size(c.oid)) AS table_size,
       pg_size_pretty(pg_indexes_size(c.oid)) AS indexes_size,
       c.reltuples::bigint AS estimated_rows
FROM pg_class c
JOIN pg_namespace n ON n.oid = c.relnamespace
WHERE c.relkind IN ('r', 'p', 'm')
  AND n.nspname NOT IN ('pg_catalog', 'information_schema')
ORDER BY pg_total_relation_size(c.oid) DESC
LIMIT 20