Высокое использование ЦП в машине RHEL

Your screenshot shows that some client using IP adress 10.5.183.37 is running some select query. This client connected at 00:46 and it's corresponding Postgres process has used over 57 minutes of processor time.

Search for a cron job on a computer with IP adress 10.5.183.37 starting every day at about 00:46.