多项选择题
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?（）
多项选择题 Consider typical High Availability (HA) solutions that do not use shared storage. Which three HA solutions do not use shared storage?（）
单项选择题 Consider the query: Mysql＞ SET @run = 15; Mysql＞ EXPLAIN SELECT objective, stage, COUNT (stage) FROM iteminformation WHERE run=@run AND objective=’7.1’ GROUP BY objective,stage ORDER BY stage; The iteminformation table has the following indexes; Mysql＞ SHOW INDEXES FROM iteminformation: This query is run several times in an application with different values in the WHERE clause in a growing data set. What is the primary improvement that can be made for this scenario?（）
