A.Do not pass a user variable in the WHERE clause because it limits the ability of the optimizer to use indexes
B.Add an index on the objective column so that is can be used in both the WHERE and GROUP BY operations
C.Drop the run_2 index because it has caused a conflict in the choice of key for this query
D.Execute the run_2 index because it has caused a conflict in the choice of key for this query
E.Add a composite index on (run,objective,stage) to allow the query to fully utilize an index

A.It prompts you to set the root user account password
B.It checks whether file permissions are appropriate within datadir
C.It asks to remove the test database, which is generated at installation time
D.It can delete any anonymous accounts
E.It verifies that all users are configuration with the longer password hash