Information search system

An information search system, comprising:

• a database configured to store a plurality of pieces of information that are text-searchable;
• a query sentence acceptance unit configured to accept a query sentence in a natural language format;
• an inputted search keyword extractor configured to extract an inputted search keyword from the query sentence;
• a retrieval executor configured to execute retrieval processing from the database using the inputted search keyword, along with a keyword relevant to the inputted search keyword;
• a local management apparatus configured to store district material in a local database;
• and
• an information management apparatus configured to execute character extraction processing on the material stored in the local database and convert a file format of the material according to a size thereof, store the material in a temporary memory as stored material, and output the stored material to the database,
• wherein, in a case in which the size of the material is less than or equal to a threshold, the information management apparatus converts the material to a first file format, and in a case in which the size of the material is not less than or equal to the threshold, the information management apparatus converts the material to a second file format that includes link information to the local database,
• wherein the material includes a photograph that does not contain character information,
• wherein, in a case in which the material does not contain character information, the information management apparatus executes character extraction processing of extracting a file name and a folder path of the material as character information.