private function clearStats()
    {
        $this->queries_executed = 0;
        $this->queries_released = 0;
        $this->queries_erroneous = 0;

        $this->sentences_executed = 0;
        $this->sentences_erroneous = 0;

        $this->inserts_executed = 0;
        $this->inserts_erroneous = 0;

        $this->updates_executed = 0;
        $this->updates_erroneous = 0;

        $this->deletes_executed = 0;
        $this->deletes_erroneous = 0;
    }