School of Computer Science;
Wuhan University;
Wuhan 430072;
China;
Institute of Electronics;
Chinese Academy of Sciences;
Beijing 100190;
China;
CAS Key Laboratory of Optical Astronomy;
National Astronomical Observatories;
Chinese Academy of Sciences;
Beijing 100101;
China;
astronomical databases:catalogs; (galaxies:)quasars:general; methods:statistical; techniques:miscellaneous;