New applications such as sensor data monitoring and mobile device tracking, rise up the issue of uncertain data management. Compared to \"Certain\" data, the data in the uncertain database are not exact points, which, instead, often reside within a region. Here, the study ranked queries over the uncertain data. The existing system such as decision making, recommendation raising, and data mining tasks proposes only for certain data. The authors define several fundamental properties including performance, radius range, unique-range, value-invariance and stability.