Writes on databases are first done in memory and then persisted in the disk. This principle is applied to the process of writing data as well as that of writing corresponding logs. Consider this principle to answer this question.

Explain how a database system handles writes (e.g. Update X with Y)in terms of the following actions:

- The log entry of this update is written in the memory.

- Data is updated in memory.

- The log entry is persisted on disk.

- Updated data is persisted on disk.