But the specific either to do processing in the application layer, similar to Taobao's early practice, the application is required to distinguish between the back-end of the database,

Or you need to establish a data access layer, by the data access layer to deal with the back-end of the database split, similar to the Taobao later practice,

Specific

Specifically, you can go to the library to search Taobao distributed database and other articles to see.

Specifically, you can search the library for articles on Taobao distributed database.