The application is in restaurant.py . The files.txt (eg AFORA.txt) are the data from the random generator to fill the database in the code insert_data_from_file.py or ins_r1.py, ins_r2.py . The r20, r1000, r5000 (_index / _noindex .db) are the databases each with and without indexes that are used at the files time_query1(/2/3).py for statistics reasons about the need of indexes that are shown in file diagram_time.py . Also, there are some extra queries in SQL in files SQL_queries.py and SQL_queries_new.py.