MySQL Logic architecture (layer three)

1, the client (main processing connection, authorization authentication, security, etc.).

2, the MySQL server layer (core service functions are in this layer, including, query parsing, analysis, optimization, caching and all the built-in functions, all the functions of the cross-storage engine are implemented in this layer: stored procedures, triggers, views, etc.).

3, Storage engine layer (responsible for the storage and extraction of data in MySQL, the server communicates with the storage engine through the API. These interfaces mask the differences between different storage engines. The storage engine does not parse SQL,InnoDB is an exception that resolves the foreign key definition. different storage engines do not communicate with each other, just a simple layer server request. ）