单项选择题 A senior DBA asked you to execute the following command to improve performance: SQL> ALTER TABLE subscribe log STORAGE (BUFFER_POOL recycle); You checked the data in the SUBSCRIBE_LOG table and found that it is a large table containing one million rows. What could be a reason for this recommendation?（）

单项选择题 You are administering a database and you receive a requirement to apply the following restrictions: 1. A connection must be terminated after four unsuccessful login attempts by user. 2. A user should not be able to create more than four simultaneous sessions. 3. User session must be terminated after 15 minutes of inactivity. 4. Users must be prompted to change their passwords every 15 days. How would you accomplish these requirements?（）

多项选择题 You administer an online transaction processing (OLTP) system whose database is stored in Automatic Storage Management (ASM) and whose disk group use normal redundancy. One of the ASM disks goes offline, and is then dropped because it was not brought online before DISK_REPAIR_TIME elapsed. When the disk is replaced and added back to the disk group, the ensuing rebalance operation is too slow. Which two recommendations should you make to speed up the rebalance operation if this type of failure happens again?（）