多选题Which three statements are true about memory buffer allocation by a MySQL Server?（）AGlobal buffers such as the InnoDB buffer pool are allocated after the server starts, and are never freedBThread buffers are allocated when a client connects, and are fr
题目
多选题
Which three statements are true about memory buffer allocation by a MySQL Server?（）
A
Global buffers such as the InnoDB buffer pool are allocated after the server starts, and are never freed
B
Thread buffers are allocated when a client connects, and are freed when the client disconnects
C
Buffers that are needed for certain operation are allocated when the operation starts, and freed when it ends
D
User buffers are allocated at server startup and freed when the user is dropped
E
All dynamic buffers that are set with a SET GLOBAL statement immediately get allocated globally, and are never freed