what are the uses of DB2_MMAP_WRITE and DB2_MMAP_READ

I know by degault these are on. How do we know when these params need to be turned off. I have seen lot of times , turning these params off is improoving the performance

What are the monitor elements i should check to turn them off or on

Thx

If you set those variable to on, you tell DB2 to by-pass the operating system's memory cache: http://publib.boulder.ibm.com/infoce..._DB2_MMAP_READ