How do you find the disk size of a Postgres / PostgreSQL table and its indexes

Question

I\'m coming to Postgres from Oracle and looking for a way to find the table and index size in terms of bytes/MB/GB/etc, or even better the size for all tables.

Answer 1

The Query below will serve you

SELECT nspname || '.' || relname AS "relation",
  pg_size_pretty(pg_total_relation_size(C.oid)) AS "total_size"
FROM pg_class C
LEFT JOIN pg_namespace N ON (N.oid = C.relnamespace)
WHERE nspname NOT IN ('pg_catalog', 'information_schema')
  AND C.relkind <> 'i'
  AND nspname !~ '^pg_toast'
ORDER BY pg_total_relation_size(C.oid) DESC
LIMIT 20;

See this Link: https://wiki.postgresql.org/wiki/Disk_Usage