Someone ask me a question. Let's say we have following tables: tb_person(person_id, name, age, sex, location), tb_city(city_id, population, ..., name). tb_person.person_id points to tb_city.city_id. There are so many records in both tables. He seperate the tb_person into like: tb_person_in_shanghai, tb_person_in_Beijing, etc. He deleted location field to let the records to be less to improve the performance when query. I think that looks ugly. Do you think it's a right way or you have any other good idea?

you may tell him that's a terrible design

what is the right way to implement that?

Thanks

only two tables in total -- one for people, one for cities

how to increase the performance with the much larger data?

Can we add an index on table?

absolutely yes, you need indexes