To enable pg_stat_statements, add pg_stat_statements to shared_preload_libraries in the DB parameter group

SELECT
	query,
	calls,
	total_exec_time,
	rows
FROM
	pg_stat_statements
ORDER BY
	total_exec_time DESC
LIMIT
	5;

в RDS Aurora нужно включить предварительно pg_stat_statements, добавив в группе параметров pg_stat_statements в список shared_preload_libraries

SELECT
	query,
	calls,
	total_exec_time,
	rows
FROM
	aurora_stat_statements()
ORDER BY
	total_exec_time DESC
LIMIT
	5;

SELECT * FROM pg_stat_activity WHERE state = ‘active’;
SHOW max_connections;

SELECT
  pid,
  now() - pg_stat_activity.query_start AS duration,
  query,
  state
FROM pg_stat_activity
WHERE (now() - pg_stat_activity.query_start) > interval '5 minutes';