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 value of a desired size, the desired size being an amount 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, the compressed memory pool being usable with the memory to make the desired size of the expanded memory available for use with the workload in the data processing system; 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.