Assume a hierarchical memory system having a joint instruction/data cache with a memory - access cost of 10 ns on a hit and 90 ns on a miss. an alternative design without hierarchical memory architecture has a memory - access cost of 70 ns. what is the minimum cache - hit percentage that would make the hierarchical memory system useful?

George heard about the benefits of a data warehouse. he wants to try implementing one for his organization. however, he is afraid that transferring data to the data warehouse will affect transaction time. which element ensures that transactions are not affected when moving data to a warehouse? when data is transferred to a data warehouse, the a area frees the source system to continue transaction processing.