1. A method for determining an optimal cache size of a computing system, the method comprising: selecting a portion of an address space of a memory structure of the computing system; monitoring a workload of data transactions to identify a subset of the workload containing one or more transactions directed to the portion of the address space; for each transaction of the one or more transactions of the subset: identifying an address of the transaction within the portion of the address space; determining a count of addresses within the portion of the address space having respective accesses times more recent than or equal to an access time associated with the identified address; and determining, from the count, a minimum cache size to service the transaction; and determining, based on the minimum cache size, an optimal cache size satisfying a performance target.