message: Update number-of-trusted-contacts-of-a-customer.sql
diff: -# Time: O(n + m + l), n, m, l are the sizes of invoices, customers, contacts
  +# Time: O(n + m + l + nlogn), n, m, l are the sizes of invoices, customers, contacts
  # Space: O(n + m + l)
  SELECT i.invoice_id,
  