Reverse index intersection method

The invention discloses a reverse index intersection method which comprises the following steps of: pre-processing; drawing a two-dimensional scatter diagram by taking the index of docID as a transverse coordinate and the value of the docID as a longitudinal coordinate; generating a linear regression straight line based on a least square method to ensure that the sum of squares of vertical deviations among all points in a figure and the straight line is minimized; evaluating a left safe search range and a right safe search range; and storing evaluated linear regression information. During reverse index intersection, the safe search range of the docID to be searched in a reverse list is determined according to the stored linear regression information of the reverse list, and a certain existing search method is adopted to search in the range. By adopting the reverse index intersection method disclosed by the invention, the search range can be reduced, the search time can be shortened, the response time of a sea