I saw only 6.3.
Memory, system application persistence layer concept.
Random access memory
It is divided into two kinds of static and dynamic, static faster and more expensive. Each bit static RAM in the memory unit in a bi-stable, steady-state left and right, an unstable state. It makes me think of the 0 and 1 ......
Dynamic each bit is stored as charge on a capacitor. Each unit consists of access transistors and a capacitor, but the leakage will not be restored.
Under summary, static faster than dynamic, stored more durable, but very expensive.
Disk, very slowly, through a turntable needle to find something specific, should be that we are using a mechanical hard drive. Write operation of the magnetic head is stored in the write bit surface, called seek.
· SSD.
Storage technology trends, fast is better than slow expensive, after all, is the price and performance trade-off process, to work as usual in demand and technology trade-offs.
Locality, local time and spatially localized, cited once memory location will be referenced again in the near future, a local memory location is referenced will be a reference to a memory location in the vicinity in the near future. The original concept is in this book.
Memory hierarchy. Register, L1, L2, L3 cache, main memory, a local disk, the remote secondary storage.
Can improve the efficiency of using the principle of locality.