SAP HANA: Interview Questions 71 through 80

71. How does SAP HANA support Massively Parallel Processing? 

With the availability of Multi-Core CPUs, higher CPU execution speeds can be achieved. Also, HANA Column-based storage makes it easy to execute operations in parallel using multiple processor cores.  
In a column store data is already vertically partitioned. This means that operations on different columns can easily be processed in parallel.
If multiple columns need to be searched or aggregated, each of these operations can be assigned to a different processor core.  
In addition operations on one column can be parallelized by partitioning the column into multiple sections that can be processed by different processor cores. 
With the SAP HANA database, queries can be executed rapidly and in parallel. 

72.What are the different compression techniques? 

There are three different compression techniques 

Run-length encoding 

Cluster encoding 

Dictionary encoding 

73.What is the role of the transaction manager and session? 

The transaction manager coordinates database transactions and keeps a record of running and closed transactions. When a transaction is rolled back or committed, the transaction manager notifies the involved storage engines about the event so they can run necessary actions. 

74.Define Five-minute rule? 

It is a rule of thumb for deciding whether a data item should be kept in memory, or stored on disk and read back into memory when required. The rule is “randomly accessed disk pages of cache are reused every 5 minutes”. 

75. Define Stall? 

Waiting for data to be loaded from main memory into  the CPU cache is called as Stall. 

76. What are the steps for data provisioning into SAP HANA using Data Services? 

Choose a source database 

Choose tables to replicate 

Choose a target database (within HANA) 

Choose a runtime repository 

Execute the replicate job 

77.What are the methods to create a new table in SAP HANA? 

Right-click on the table node 

SQL script 

HAN studio import 

78.What is Analytic Privilege in SAP HANA? 

Analytic Privileges are used to restrict read access to data in SAP Information Models. They are evaluated during query processing. 

79.What minimum permissions are required to perform Modelling Activities? 

As a HANA Modeler you would perform activities like create, activate, and data-preview on views and analytic privileges. 

Following are the permissions required to perform the above: 

• SQL Privileges 

•  _SYS_BI - SELECT privilege 

•  _SYS_BIC - SELECT privilege 

•  REPOSITORY_REST (SYS) - EXECUTE privilege 

•  <<schema_where_tables_reside>> - SELECT privilege 

• Analytic Privileges 

•  _SYS_BI_CP_ALL 

• Package Privileges 

•  Root Package - REPO.MAINTAIN_NATIVE_PACKAGES privilege 

•  <<package_used_for_content_objects>> - REPO.READ, REPO.EDIT_NATIVE_OBJECTS & REPO.ACTIVATE_NATIVE_OBJECTS 

80. What is HANA Composite Provider? 

CompositeProvider is a new provider type in BW 7.30 designed to easily connect BW managed data to non-BW managed data leveraging the full power of SAPs in-memory technology(either BWA or HANA). 

To model a CompositeProvider, either BW backed transaction RSLIMO/RSLIMOBW or the Workspace Designer can be used.