IO - Random and Sequential Access
About
Random access (sometimes called direct access) is the ability to access an arbitrary element of a sequence in equal time.
Random definition: can be accessed in any order
Random refers to the idea that any piece of data can be returned in a constant time, regardless of its physical location and whether or not it is related to the previous piece of data.
The opposite is sequential access, where a remote element takes longer time to access.
Articles Related
Example
Device
Computer - Storage Device (Media)
Be careful as accessing media randomly as opposed to sequentially, typically yields minimum throughput.
random access device
A compact disc: You can jump right to the track you want.
sequential access device
a cassette tape, magnetic discs and optical discs
By contrast, storage devices such as magnetic discs and optical discs rely on the physical movement of the recording medium or a reading head. In these devices, the movement takes longer than data transfer, and the retrieval time varies based on the physical location of the next item.
With a cassette tape, you have to fast-forward through earlier songs to get to later ones. This type storage devices rely on the physical movement of the recording medium or a reading head. The movement takes longer than data transfer, and the retrieval time varies based on the physical location of the next item.