FAQ: Cross-Database-Access (CDA) in BW systems and HANA MDC (Multitenant Database Containers)
Multiple isolated databases is supported by SAP HANA in a single SAP HANA system which is referred as multitenant database containers. A SAP HANA system is capable of containing more than one multitenant database container when its is installed in multiple-container mode.
Although database objects such as tables, schemas, procedures, views, etc are local to the database, cross-database SELECT queries are possible. This particularly supports cross-application reporting in MCOS (multiple components in one system) scenarios.
What are the Documentation about HANA Multitenant Database Container?
Please find the general information regarding HANA Multitenant Database Container in the SAP HANA Administration Guide at help.sap.com.
Cross-Database-Access in SAP Business Warehouse (BW) - Features, Availability
As of SAP_BW 7.50 SP4, Cross-Database-Access is supported by the new BW DataSource / Source System for HANA (refer to SAP 2175904 for more information)
In SAP_BW 7.50 SP4, the implementation of SAP 2335786 is required (contained in SAP_BW 7.50 SP5)
As of SAP_BW 7.50 SP5, the Open ODS View does also support Cross-Database-Access.
HANA - Supported Versions
In order to use BW features related to Cross-Database-Access, you should at least have HANA SP12. HANA SP11 is currently not supported for this workflow.
Following are the required Configuration Steps
- For allowing queries across tenant database, first you must enable cross-database access and then specify which databases may communicate with one other. To do this you can configure global.ini system properties file in the SAP HANA Studio.
- Next step is to create remote identities for those users who requires cross-database access. For more information, refer Cross-Database Authorization in Multitenant Database Containers in the SAP HANA Security Guide. In order to run a query or create an object in one database for a user in other database, the user must be mapped to a sufficiently privileged user in the remote database.
- The remote tenant database must be made visible in BW Metadata, otherwise the source system creation context help will not work properly. Run Report RSDS_SETUP_HANA_MDC for adding, deleting or showing the system IDs of remote database tenants used in BW
Afterwards, check your configuration as explained in the next step.
HANA Metadata required for MDC in BW
BW needs to be able to access several HANA system views in the remote tenant database. Currently, the following system views are required:
Report RSDS_CHECK_HANA_MDC can be used to check whether the BW system can access these system views in the remote tenant database or not.
For BW 7.50 SP04, please implement SAP 2338667 to remove an incorrect error message because of monitoring view SYS.CS_VIEW_PARAMETERS.
Supported Remote Objects
With BW, currently the following object types can be accessed on remote tenant databases:
- Rowstore and Columnstore tables
- SQL views
- Calculation views