SAP HANA (High-performance Analytic Appliance) is a multi-model database that stores data in its memory instead of keeping it on a disk. The column-oriented in-memory database design allows you to run advanced analytics alongside high-speed transactions – in a single system.
Why is this so important? Because it lets companies process massive amounts of data with near-zero latency, query data in an instant, and become truly data-driven. By storing data in column-based tables in main memory and bringing online analytical processing (OLAP) and online transactional processing (OLTP) together.

What Is Data Recovery?

In computing, data recovery is a process of salvaging deleted, inaccessible, lost, corrupted, damaged, or formatted data from secondary storage, removable media, or files, when the data stored in them cannot be accessed in a usual way.
The data is most often salvaged from storage media such as internal or external hard disk drives (HDDs), solid-state drives (SSDs), USB flash drives, magnetic tapes, CDs, DVDs, RAID subsystems, and other electronic devices. Recovery may be required due to physical damage to the storage devices or logical damage to the file system that prevents it from being mounted by the host operating system (OS).

How does Data Recovery work?

Data recovery work in 2 stages. RTO and RPO
1. RTO is the target time in the future to get your application back online and running after a disaster has struck.
2. RPO is the target time in the past from which the system will be restored. The goal here is to determine the time between data backups and the amount of data that could be lost in between backups during a disaster event.

Methods for SAP HANA Recovery.

SAP HANA support 3 types of data recovery and users can choose one of these recovery options according to their business requirements.
1. Backups and recovery
2. Storage replication
3. System replication.

Backups and Recovery

SAP HANA support 3 types of backups and recovery options and they are as follows.
1. Full Data backup. The data backup process is asynchronous. The SQL data and the undo log are saved to storage to ensure a speedy restart.
2. Incremental Backup. These are the smallest delta data backup as only the changed data is backed up at frequent intervals after the last full or delta backup.
3. Differential Backup – It is the delta data backup that is done after the full data backup

Storage Replication

Storage replication is the process of mirroring disk content to a secondary data center with a standby SAP HANA system.
The transfer process can be either synchronous or asynchronous depending on the distance between the primary and the standby SAP HANA system.
As the distance between the primary and secondary center increases the latency time for writing the log also increases.

System Replication

SAP HANA system replication ships all data to a secondary system located at another site.
Once SAP HANA system replication is enabled, each server process on the secondary system establishes a connection with its primary counterpart and requests a snapshot of the data.
Further, all logged changes in the primary system are replicated continuously in the secondary system. Each persisted. Transaction persistence to disk log in the primary system is sent to the secondary system.


RPO and RTO Duration Comparison between 3 Methods

Full backup and etc were only back-ups of the database and it will take time to set up the system again and will take backup restore duration so RPO and RTO time was the longest.
Database replication with active and standby system services can get the latest update data from database replication so their RPO time was at a minimum but due to the active and standby system services, their RTO time was moderate.
Full system replication or HA was active in both database and system so this was the least RPO and RTO time and most effective way.

RPO, RTO, and Costs Comparison between 3 Methods

The first method, full backup, incremental backup, and differential backup were backup of the database so it will only consume your storage resource for backup storage. This method can cost you at a minimum but RPO and RTO duration will be the longest.
Database replication or storage replication will replicate your databases in real-time so your RPO and RTO duration will be moderate but because of the hardware resources according to infrastructure, it will cost you more than the backup and recovery option.
Full system replication or HA (High Availability) was not only the most effective option for RPO and RTO duration but also the most expensive option if you compare it with the last two recovery options. This option was most expensive because this will consume your infrastructure resource to replicate your whole system in active/passive or active/active according to your environment setup.