-
WAL - write-ahead log
- writing a lot of data to disk is expensive, which is why DBMSs persist a compressed version of the changes known as WAL
-
asynchronous snapshot
- In this approach everything we write is kept in-memory and later on, asynchronously, it’s snapshot is synced/ written to the drive (persisted disk/ SSD/ Hard-drive) all at once.
-
AOF - append-only file
- Very similar to the WAL strategy, It keeps track of only the changes happening. A very lightweight way of storing the changes and also gives the possibility of reconstructing the state of the system in case of failures.