Tag: persistence

Persistence in computer science refers to the characteristic of state that outlives the process that created it. Without this capability, state would only exist in RAM, and would be lost when this RAM loses power, such as a computer shutdown.
This is achieved in practice by storing the state as data in non-volatile storage such as a hard drive or flash memory.
Picture editing programs or word processors, for example, achieve state persistence by saving their documents to files.

In specific contexts, persistence can have different meaning. See persistent data structure for example.
Persistence is said to be “orthogonal” or “transparent” when it is implemented as an intrinsic property of the execution environment of a program. An orthogonal persistence environment does not require any specific actions by programs running in it to retrieve or save their state.
Non-orthogonal persistence requires data to be written and read to and from storage using specific instructions in a program,…