Which statement is true about FLUSH LOGS command?（）

单项选择题Identify a performance impact when using the Performance Schema.（）

A.There is no impact on performance
B.The overhead depends on the settings of the Performance Schema
C.There is an overhead for querying the Performance Schema but not for having it enabled
D.There is a constant overhead regardless of settings and workload

单项选择题You are having problems with connections from a specific host (192.168.1.15) not closing down correctly. You want to find the state of the threads from that host check for long-running queries. Which statement will accomplish this?（）

A.A
B.B
C.C
D.D

单项选择题Consider the Mysql Enterprise Audit plugin. Which statement is true when you identify a connection event that has used external authentication?（）

A.The attribute "STATUS" is set to the string EXTERNAL_AUTH
B.The attribute "PRIV_USER" contains the username
C.The event type that is given in the attribute "NAME" is EXTERNAL_AUTH
D.There is no differentiation between native and external authentication events
E.External authentication is managed through external auditing logs
F.The "PROXY_PRIV" user shows a username if external authentication is used

多项选择题Consider the Mysql Enterprise Audit plugin. The following event detail is found in the audit log: Which two points can be concluded from the given event?（）

A.A connection as the user kate was successful
B.A connection failed due to authentication being unsuccessful
C.A connection was attempted via socket rather than TCP
D.A connection was blocked by a firewall or a similar security mechanism
E.A connection failed because the proxy user privileges did not match the login user

多项选择题Which three statements are characteristic of the MEMORY storage engine?（）

A.It can support transactions
B.Table contents are not saved if the server is restarted
C.It cannot contain text or BLOB columns
D.It can support foreign keys
E.Each table is represented on disk as an.frm file
F.Each table has a corresponding.MYI and .MYD file