NoSQL Database -- MongoDB & Redis

Websites nowadays want the data storage more and more flexible. Under this requirement, NoSQL, non-relational database, is getting more and more pupular. The so-called non-relational database means the database that doesn’t use SQL to operate the data. Database of this kind doesn’t have a settled mode to save data, doesn’t support join in data table, and it can horizontal scale easily. There’re many kinds of NoSQLs, among them, MongoDB and Redis are the most commonly used. In the experiment, we