This parameter indicates the maximum amount of memory that can be used simultaneously by the BACKUP, RESTORE and LOAD and load recovery utilities.
Recommendation: Use the default value unless your utilities run out of space, in which case you should increase this value. If memory on your system is constrained, you may wish to lower the value of this parameter to limit the memory used by the database utilities. If the parameter is set too low, you may not be able to concurrently run utilities. You need to set this parameter large enough to accommodate all of the buffers that you want to allocate for the concurrent utilities.