45題、choose three
Which three statements are true about the purpose of checkpoints?
A) They ensure that instance recovery starts in the event of an instance failure.
B) They ensure that dirty buffers in the buffer cache are written to disk regularly.
C) They reduce the time required for recovery in case of an instance failure.
D) They ensure that all the dirty buffers are written to disk during a normal shutdown.
E) They ensure that uncommitted transactions are rolled back in case of an instance failure.
Answer：BCD
(解析：checkpoint進程就是給dbwr寫的信號，定期的保持，減少實例恢復時間，正常關閉時把所有的髒塊寫入數據文件。來自3組：1015267481)