What happens if the power goes out?
SAP HANA is a completely ACID-compliant database which is designed to have a low Recovery Point Objective (RPO). HANA writes savepoints to disk at frequent intervals, which contain a snapshot of what is in memory. In-between savepoints, HANA saves a log of each database change to a fast flash disk.
If the power goes out, HANA loads the last savepoint and then plays the logs back, to ensure consistency.