PostgreSQL

List of databases

\l

List of roles

\du

List of schemas

\dn

Check current/default schema

show search_path;

Change default schema for session

set search_path='public';

Top 10 tables

SELECT
  nspname AS schema_name,
  relname AS table_name,
  pg_size_pretty(pg_relation_size(C.oid)) AS main_data_size,
  pg_size_pretty(pg_total_relation_size(C.oid) - pg_relation_size(C.oid)) AS external_objects_size,
  pg_size_pretty(pg_indexes_size(C.oid)) AS indexes_size
FROM
  pg_class C
LEFT JOIN
  pg_namespace N ON (N.oid = C.relnamespace)
WHERE
  C.relkind = 'r'
ORDER BY
  pg_total_relation_size(C.oid) DESC
LIMIT 10;