单项选择题
A.InnoDB uses row and table-level locks, but row locks are not escalates
B.InnoDB locks only those rows that are updated
C.InnoDB only uses row locks, not page or table-level locks
D.InnoDB row locks may be escalated to page or table-level locks
E.InnoDB uses row-level or table-level locks depending on the number of rows affected
单项选择题 Which statement is true about the log-output variable?（）
单项选择题 You are investigating the performance of the server and see the following information: Events_waits_summary_global_by_event_name in the performance schema shows that the wait/synch/mutex/sql/LOCK_table_cache event is dominating other wait events. The table_open_cache_overflows status variable is 0. Which action should be taken to remove the performance bottleneck described here?（）
多项选择题 Which two statements are true about setting the per-thread buffers higher than required?（）