code: func (p *Postgres) CleanExpiredRows(expire time.Duration) (int64, error) {
  	// See: http://stackoverflow.com/questions/14465727/how-to-insert-things-like-now-interval-2-minutes-into-php-pdo-query
  	// basically by passing an integer to INTERVAL is not possible, we need to
  	// cast it. However there is a more simpler way, we can multiply INTERVAL
  	// with an integer so we just declare a one second INTERVAL and multiply it
  	// with the amount we want.
  	cleanOldRows := `DELETE FROM kite.kite WHERE updated_at < (now() at time zone 'utc') - ((INTERVAL '1 second') * $1)`
  
  	rows, err := p.DB.Exec(cleanOldRows, int64(expire/time.Second))
  	if err != nil {
  		return 0, err
  	}
  
  	return rows.RowsAffected()
  }
docs: // CleanExpiredRows deletes rows that are at least "expire" duration old. So if
  // say an expire duration of 10 second is given, it will delete all rows that
  // were updated 10 seconds ago