Which three are true about AWR snapshots?

A)They are always created automatically.

B)They are always created manually.

C)They are generated If statistics_level is set to basic.

D)They are generated If statistics_level is set to typical.

E)They are always retained forever.

F)They can be retained forever.

G)They are generated if statistics_level Is set to all.

Answer: DFG

赵：

Statistics_level：basic 禁用，typical 正常，all 全部。