4. The search system according to claim 3 , wherein the search processing unit receives a search string including a plurality of search words to generate a plurality of kinds of search tokens from the plurality of search words, and generates a search command to execute inquiries inclusive of a plurality of the parallel inquiries corresponding to the search string to calculate the sum of total scores associated with each of the plurality of search words for documents in extracted information to generate the file for the search string.
4. The search system according to claim 3 , wherein the search processing unit receives a search string including a plurality of search words to generate a plurality of kinds of search tokens from the plurality of search words, and generates a search command to execute inquiries inclusive of a plurality of the parallel inquiries corresponding to the search string to calculate the sum of total scores associated with each of the plurality of search words for documents in extracted information to generate the file for the search string. 5. The search system according to claim 4 , wherein the character string is a character string including single-byte characters, or a character string including multibyte characters comprising at least one of Chinese, Japanese, Korean, and Arabic characters.