Types of Access
- An example of a serial/sequential access is above.
- Serial access storage store data one by one in a specific order.
- The data can only be accessed in same order you record or store in.
- An example of how a serial access works.
- For example if you want a movie, you will have to rewind or fast forward to find the part you like to watch, unlike DVD’s you can choose in chapters.
- A direct/ random access is another way of accessing data. In this type of access you can you don’t need to search for what you need to find.
- In a movie if you want a find a chapter you want to watch, you can go to scene you want without fast forwarding.
- All parts of the DVD are directly accessible.
- Different storage devices have different speeds, some can be fast and some can be slow.
- Access speeds are measured in bit per second (B/s).
- Slow devices are measured in thousands of bit per second (KB/s).
- Fast devices can be measured in millions of bit per seconds (MB/s).
- Today there is a new category called Flash storage. The access speed can reach to 500mb/s. Flash storage is 4x faster than Hard Drives.