In the OceanStor V3 storage system, about the Cache high and low water level, which is correct? (Multiple choice)

In the OceanStor V3 storage system, about the Cache high and low water level, which is correct? (Multiple choice)
A . The time that IO stays in the Cache is closely related to the setting of the low water level value. When the low water level is set higher, the issued IO can get more integration opportunities, thus improving the performance of random writes.
B . When the business pressure is high, you can increase the high water level appropriately, avoid frequently triggering the high-speed brushing, and make the system stable in the middle and low speed brushing.
C . When the write strategy is write-back, the Cache controls the storage capacity and the brush rate of dirty data through the high and low water levels.
D . By default, the low watermark value set by the system is 20. In the Oracle OLTP service scenario, the low water level can be appropriately increased to optimize the write performance.

Answer: ACD