SAP HANA Admin - Multitenant Database

It is possible to set up multiple databases into a single HANA system. When you install SAP HANA system in multiple container mode, you can setup multiple isolated databases in single SAP HANA system. This is called Multitenant database containers.

You can also covert a single container HANA system to multiple container databases HANA system. In multiple container HANA system, each database runs on the same infrastructure and uses the same computing resources. However, each database contains following components −

• Database Users
• Repository
• Catalog
• Backups
• Traces and Logs
• Persistence

All the database objects - tables, schemas, database views, SQL procedures - are separate for each database. You can also perform cross-database functions in multitenant database.

In SAP HANA system, it contains multiple server - Name Server, Index Server, Preprocessor, and XS Server. With multiple container databases, different combinations of the above servers are used.

Name server maintains the landscape details of the system and the system databases run the Name server. The Name server of multitenant databases doesn’t contain topology information and this information is stored in tenant database catalog.

Preprocessor and Compile server runs on system databases as they don’t contain persist data. Each tenant database contain its own index server and SAP HANA Classic Server runs on the Index server of tenant database by default.

You can see the architecture of SAP HANA multiple container system in the following screenshot. Each instance of system database runs on multiple hosts to provide scalability and system availability. In multiple worker configuration, when a system fails, standby instance will fail over all active databases.

In the above screenshot, you can see 2 databases distributed across three hosts in multiple container database system.

In multiple container architecture, the system database is set up at the time of installation of a multiple-container system or when you convert a single container system to multiple container system. This is used to manage information about the system as a whole, and also for tenant databases. It is used for Central System Administration in multitenant environment.

System database contains data and user data for system administration and SAP HANA Administration tools such as SAP HANA Studio to connect to the system database. All the administration tasks that are performed in the system database applies to the whole system and you can also target the configuration for a specific tenant database. System database contains complete landscape information about Tenant components, however it doesn’t contain topology related information.