单项选择题
A. The cached result becomes invalid when any structural change is done to the EMPLOYEES table.
B. If the function execution results in an unhandled exception，the exception result is also stored in the cache.
C. Each time the function is invoked in a different session，the current result in the result cache gets overwritten.
D. If the function is invoked with a different parameter value，the existing result in the result cache gets overwritten by the latest value.
单项选择题 You want to use RMAN to create compressed backups. Which statement is true about the compression algorithms that RMAN can use？（）
单项选择题 You have the following requirements in relation to the detection of block corruption for your database instance： Check for logical self-consistency of data blocks when modified in memory. Checksums are calculated before and after the block change. Checks are performed for the lost writes to the physical standby database. Which method would help you perform the above checks automatically？（）
单项选择题 Examine the following command： ALTER DISKGROUP data MOUNT FORCE； In which scenario can you use the above command to mount the disk group？（）