Once the MEMORY RESIDENT option is set for a structure, the buffers used by the structure stay in memory until the last user of a structure closes the database or until the MEMORY RESIDENT option is explicitly reset through the Visible DBS facility.

Specifying TRUE or FALSE enables or disables the option respectively. Specifying ALL is equivalent to specifying TRUE and is retained for historical purposes. Note that the buffers become permanent residents only when they are accessed. Memory is not prefilled.

If you are considering using the MEMORY RESIDENT option to improve Enterprise Database Server performance, Unisys recommends instead, using more ALLOWEDCORE with larger system buffers.