Abstract: Currently, there arc many ranking methods sorted by correlation in relational databases.()均cct level retrieval can integrate information which is dispersed in many tuples into complete information. As each object is unique, the difference among the objects is not only embodied in the keywords, but also embodied in the attribute values which they contain. Thus,this article described a method which gathers statistics of the distribution of attribute values in the object which contains the keyword, and makes use of the information entropy method to assign weights for each attribute value to calculate the correlation score of each tuple to each keyword. In the end, the object's score for each keyword is summed up to get the final ranking score for the object.

Key words: Relational databases,Object level,Ranking algorithm,Attribute value,Information entropy