23. The method according to claim 22 , wherein the query is sorted after eliminating stop words from the query, and the determining in step (a) is performed by utilizing an improved binary searching algorithm, wherein an index location of a previously matched keyword is used as a start searching index for subsequence keywords of the query.
22. The method according to claim 16 , wherein said searching said sorted database comprises: for each file of said sorted files: aâ€”determine a number of unmatched keywords in the query; bâ€”if the number of unmatched keywords is greater than a predetermined number, skip the current file and go to next file; câ€”if the number of unmatched keywords is not greater than said predetermined number, storing the filename of the current file to a list of files-of-interest and go to next file.