Index Server is the main component of SAP HANA Architecture. It consists engines and actual data for data processing. The Index Server takes care of all the requests and processes them. Complete processing of SAP HANA is done in Index Server.It processes incoming SQL or MDX statements which comes to SAP HANA database system.
The components of Index Server are:
- Connection and Session Manager
It manages all database transactions and tracks all the transactions. Whenever a transaction completes or fails, the transaction manager informs suitable data engine to perform relevant actions.
- Persistence Layer
The Persistence Layer utilizes existing feature of Disaster Recovery for SAP HANA Database. It also manages data and transaction logs and consist log backup and data backup of SAP HANA system.
- Planning Engine
The planning engine in SAP HANA Architecture creates SQL processing plans.
It generates a plan particular to each request sent to HANA database. It handles the different levels of aggregations which are applied to data.
- Calc Engine
It modifies data into calculation models for creating logical execution plan to handle parallel processing of statements.
It continues the versioning of SAP HANA metadata object like stored procedure.
Learn in detail - https://data-flair.training/blogs/sap-hana-architecture/