db->insert error

PHP Code:

        for($i = 0; $i < 1000000;$i++){
            $uid = uniqid('rsv', true);

            $this->db->set('uid',$uid);
            $this->db->set('data','toto' . $i);
            $this->db->reset_query();
            if ( $this->db->insert('ddr') == false ){

                break;
            }
            $this->db->reset_query();
        } 


Error message Fatal error: Allowed memory size of 134217728 bytes exhausted  in /system/database/DB_driver.php on line 703