What is SAP HANA Index Server?
SAP HANA Index Server is the main server which contains data and handles all other servers. It also processes all the commands and hence provides a good security and data protection and enhanced data access.
Below are the various components of SAP HANA Index Server:
1) Connection & Session Management
Connection & Session management that initializes and manages sessions and connections for the SAP HANA database using pre-established session parameters to accommodate complex securities and data transfer policies.
2) SQL Processor
SQL Processor that segments data queries and directs them to speciality query processing engines for optimised performance. It also ensures that SQL statements are accurately authored and provides error handling to make these queries more efficient. The engines under SQL Processor are-
- Multi Dimensional Expression (MDX) Engine that manipulates the multi-dimensional data stored in OLAP and handles all the queries.
- Planning Engines that enables the basic planning operations within the basic HANA database for financial planning operations.
- Store Procedure Processor that executes procedural calls for optimised processing without re-interpretation. It is only meant for store procedural calls.
- Calculation Engine that converts all the data into calculation models and creates logical execution plans to support parallel processing.
3) Relational Stores
Relational Stores that are the segmented compartments of storage that stores in-memory data which provides easier access. Data is stored row wise.
There are four Relational Stores that optimize query performance-
- Row Store that stores the table records in a sequence of rows.
- Column Stores that stores the table records in the sequence of columns.
- Disk Based Store in which when the data is not required then it is stored in the disk and not stored in the memory.
- Object Store is the integration of SAP Livecache Technology into SAP HANA database system.
4) Transaction Manager
Transaction Manager that is the component that coordinates database transactions and it takes care of controlling transaction isolation and it keeps track of running and closed transaction. It cooperates with the persistence layer to achieve atomic and durable transactions.
5) Metadata Manager
Metadata Manager that helps to access the metadata. It contains a variety of objects like the definition of tables, views, indexes, SQL script function, object store metadata. It manages all the metadata of the entire SAP HANA database which is stored in the row store. Features such as transaction support and multi version conferencing control are also used for metadata management.
6) Persistence Layer
Persistence Layer that is responsible for durability and atomicity of the transactions. It ensures that the database is restored to the most recent committed state after restart, and makes sure that the transactions are either completely executed or completely rolled back. It also offers an interface for writing and reading data and contains the SAP HANA's Logger that manages the transaction log, and also the page management.
7) Authorization Manager
Authorization Manager that is invoked by other SAP HANA database components to check the required privileges for users to execute the requested operations.
Authentication that can be delegated to the external authentication provider or third parties for authenticating or giving authorizations of analytical privileges.