1. A computer usable program product comprising a computer usable storage device including computer usable code for expanding memory size, the computer usable code comprising: computer usable code for receiving in a data processing system having a memory, a desired size of an expanded memory; computer usable code for receiving a first information about a workload in the data processing system; computer usable code for computing a size of a compressed memory pool to use with the memory to make the desired size of the expanded memory available; computer usable code for configuring a representation of the memory, the representation of the memory appearing to be of a size larger than the size of the memory, the representation of the memory being the expanded memory, and the size of the representation being the size of the expanded memory; and computer usable code for making available the expanded memory such that the memory in the data processing system is usable by addressing the expanded memory.