SAP HANA Architecture

Data is compressed by different compression techniques (e.g. dictionary encoding, run length encoding, sparse encoding, cluster encoding, indirect encoding) in SAP HANA Column store.

When main memory limit is reached in SAP HANA, the whole database objects (table, view,etc.) that are not used will be unloaded from the main memory and saved into the disk.

These objects names are defined by application semantic and reloaded into main memory from the disk when required again. Under normal circumstances SAP HANA database manages unloading and loading of data automatically.

However, the user can load and unload data from individual table manually by selecting a table in SAP HANA studio in respective Schema- by right-clicking and selecting the option "Unload/Load".

SAP HANA Server consists of

1. Index Server
2. Preprocessor Server
3. Name Server
4. Statistics Server
5. XS Engine