单项选择题
You have a server that has very limited memory but has a very large table. You will use mysqldump to back up this table. Which option will ensure mysqldump will process a row at a time instead of buffering a set of rows?（）
A.— quick B.— skip-buffer C.— single-transaction D.— tab
多项选择题 Which three tasks can be performed by using the performance Schema?（）
多项选择题 Which three statements are true about memory buffer allocation by a MySQL Server?（）
单项选择题 Consider the following: Which statement best describes the meaning of the value for the key_len column?（）
