SAP HANA Modelling Interview Questions And Answers Pdf
1. What is the operating system supported by HANA?
Answer: Currently SUSE Linux Enterprise Server x86-64 (SLES) 11 SP1 is the Operating System supported by SAP HANA.
2. Explain how you can avoid unnecessary logging information from being stored?
Answer: You can avoid unnecessary logging information from being stored by pausing the replication by stopping the scheme-related jobs.
3. There are 2 types of packages in content. What are they?
Answer: In the HANA, 2 types of packages can be created.
Structural: Package only contains sub-packages. It cannot contain repository objects.
Non-Structural: Package contains both repository objects and sub-packages.
By default it creates Non-structural.
4. What are the different types of calculation view? Which one would you prefer?
Answer: There are 2 types of calculation view possible.
Graphical calculation view
Scripted calculation view
Graphical calculation views are created using the graphical editor. Scripted calculation views are created using the SQL Editor.
Graphical based calculation views offer better performance compared to SQL based calculation views.
But in scenarios where graphical calculation views cannot implement business logic, we need to use scripted calculation view. Complex calculations which are not possible thru graphical approach can be created using SQLScript.
5. How you can use Data provisioning in SAP HANA studio?
Answer: Go to SAP HANA Modeler Perspective → Data Provisioning.
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6. What is the importance of _SYS_BI_CP_ALL analytic privilege?
Answer: _SYS_BI_CP_ALL analytical privilege gives access to read from all information model views. We can control this by creating our own analytical privileges and assigning it to only the views that a user should be reporting against and at the level they want to view data.
If a user has the _SYS_BI_CP_ALL Analytic Privilege assigned all other restrictions are ignored. This is generally used for developer roles.
7. What is ad hoc analysis?
Answer: In traditional data warehouses, such as SAP BW, a lot of pre-aggregation is done for quick results. That is the administrator (IT department) decides which information might be needed for analysis and prepares the result for the end-users. This results in fast performance but the end-user does not have flexibility.
The performance reduces dramatically if the user wants to do analysis on some data that is not already pre-aggregated. With SAP HANA and its speedy engine, no pre-aggregation is required. The user can perform any kind of operations in their reports and does not have to wait for hours to get the data ready for analysis.
8. Which all Business Objects tools can be directly connected to HANA Information views?
Analysis edition for OLAP
SAP Crystal Reports
9. What are the row-based and column-based approach?
Answer: Row-based tables:
It is the traditional Relational Database approach
It stores a table in a sequence of rows
Column based tables:
It stores a table in a sequence of columns i.e. the entries of a column is stored in contiguous memory locations.
SAP HANA is particularly optimized for column-order storage.
SAP HANA supports both row-based and column-based approach.
10. How to get sap Hana performance solutions?
Answer: Like any other database, sap Hana could suffer from a low performance at one stage. It is therefore important to have a monitoring strategy in place in order to catch any performance issues. Reasons for slow performance are known and advice is available.
11. How to troubleshoot sap, Hana?
Answer: Errors in sap Hana can happen and would be coming from various areas such as SQL script execution, in Memory Data growth, change of configuration, disk, CPU, and memory issues.
12. What is the Purpose of SUM and LM structures?
Answer: SUM allows automatic download and installation of SAP HAN versions and upgrades from SAP Marketplace. LM structure stores details on the current product version installed.
13. How to manage Hana users step by step?
Answer: A user has to be assigned the necessary privileges in order to work with sap Hana database. Predefined privileges are available and ready to be granted to specific users such as Operation-users, Monitoring-User, backup-user.
14. What is Configuration and Monitoring Dashboard?
Answer: It is an application that runs on SLT replication server to specify configuration information (such as source system, target system, and relevant connections) so that data can be replicated. It can also use it to monitor the replication status (transaction LTR).
Status Yellow: It may occur due to triggers which are not yet created successfully.
Status Red: It may occur if the master job is aborted (manually in transaction SM37).
15. What are Transformation rules?
Answer: A rule specified in the Advanced Replication settings transaction for source tables such that data is transformed during the replication process. The example you can specify a rule to
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16. What happens when you set-up a new configuration?
Answer: The database connection is automatically created along with GUID and Mass transfer id (MT_ID).
A schema GUID ensures that configurations with the same schema name can be created. The Mass transfer ID is used in the naming of SLT jobs and the system can uniquely identify a schema.
17. What is the relation between the number of data transfer jobs in the configuration settings and the available BGD work processes?
Answer: Each job occupies 1 BGD work processes in SLT replication server. For each configuration, the parameter Data Transfer Jobs restricts the maximum number of data load job for each mass transfer ID (MT_ID).
18. What is the best way to manage, operate, and monitor sap Hana systems?
Answer: Sap Hana is a young database with interesting features of SAP HANA. First of all Sap Hana is an in-memory database. It is accessible for administration via various channels. Directly from the Server, It is not the most convenient method but you can use hdbsql to manage databases. With the web-based interface Hana cockpit, you can browse and manage sap Hana environments. The Client Hana Studio is the most complete tool to administer Sap Hana but it has to be physically installed and therefore is dependent on the client hardware.
19. How does SAP HANA support import from a local file?
Answer: This is used to import data from a flat-file like .xls or.csv file. Click on Next → Choose Target System → Define Import Properties.
Select the Source file by browsing the local system. It also gives an option if you want to keep the header row. It also gives an option to create a new table under existing Schema or if you want to import data from a file to an existing table.
20. List advantages of column-based tables?
Answer: Allows smoother parallel processing of data as the data in columns is stored vertically. Thus, to access data from multiple columns, every operation can be allocated to a separate processor core.
Efficient operations since most columns hold unique values and thus, high compression rate.
Only specific columns need to be approached for Select query and any column can be used for indexing.
21. Mention what is SAP HANA?
Answer: SAP HANA stands for High-Performance Analytical Appliance- in-memory computing engine. HANA is linked to ERP systems; Frontend modeling studio can be used for replication server management and load control.
22. Mention what is the advantage of SLT replication?
Answer: SAP SLT works on trigger-based approach; such an approach has no measurable performance impact in the source system
It offers filtering capability and transformation
It enables real-time data replication, replicating only related data into HANA from non-SAP and SAP source systems
It is fully integrated with HANA studios
Replication from several source systems to one HANA system is allowed, also from one source system to multiple HANA systems is allowed.
23. Mention what is the role of master controller job in SAP HANA?
Answer: The job is arranged on demand and is responsible for
Creating database triggers and logging table into the source system
Writing new entries in admin tables in SLT server when a table is replicated/loaded
24. If my Analytic View foundation is joined to attribute views, is both the OLAP and JOIN Engine used?
Answer: Nope – during activation of the analytic views, the joins in the attribute views get ‘flattened’ and included in the analytic view run-time object. Only the OLAP engine will be used then.
25. Which are the top five use cases in SAP HANA?
Answer: Major sap Hana use-cases are:
Real-time financial planning
Detective HANA and
26. What are the different modes in HANA studio that can be used for migration?
Change and Transport system
SAP support mode
27. Which of the export options allows you to export multiple packages locally or to another HANA system?
Answer: Delivery Unit
A delivery unit is a single unit which can be mapped to multiple packages and can be exported as a single entity so that all the packages assigned to the Delivery Unit can be treated as a single unit.
28. Why materialized aggregates are not required in HANA?
Answer: Since the SAP HANA database resides entirely in-memory all the time, additional complex calculations, functions and data-intensive operations can happen on the data directly in the database. Hence materialized aggregations are not required.
It also provides benefits like
Simplified data model
A higher level of concurrency
Simplified application logic
29. What is a new calculated column in a HANA Modeling view?
Answer: New calculated column is defined as a column added on the fly in Analysis tab when a view is activated. This column doesn’t exist at the database level or in Data Foundation or Star Join level.
30. Does SAP HANA require indexes or aggregates?
Answer: Every column in SAP HANA is stored as an index, and therefore HANA has no need for separate primary indexes. Secondary indexes with multiple columns are possible and used for OLTP scenarios like the Business Suite. HANA will also self-generate helper indexes to ensure that multi-column joins are efficient.
31. To improve the performance of Information view by validating joins and Cardinality, which option can be used?
Answer: You can select Switch to Performance Analysis Mode. This allows you to do Performance Analysis by validating correct join type and Cardinality.
32. What is the use of parameters and variables in Semantic layer?
Answer: Variables are used as an explicit SQL filter directive for view consumers to filter the view data, based on attribute column values specified in variable UI prompt of a BI Client. When you go to data preview, variables allow users to pass the value of the attribute defined in the variable.
33. What are the different authentication methods configured in SAP HANA system for user creation?
Answer: Below is the list of authentication methods supported by SAP HANA −
SAP Logon tickets
34. What is a restricted user in SAP HANA system?
Answer: Restricted users are those users who access the HANA system with some applications and they don’t have SQL privileges on HANA system. When these users are created they don’t have any access initially.
If we compare restricted users with Standard users −
Restricted users can’t create objects in the HANA database or their own Schemas.
They don’t have access to view any data in the database as they don’t have generic Public role added to profile like standard users.
They can connect to the HANA database only using HTTP/HTTPS.
35. What are SAP HANA Analytic Privileges?
Answer: Analytic Privileges are used to limit access to HANA Information views. You can assign different types of right to different users on a different component of a View in Analytic Privileges.
36. If you want that your Area Managers can only see data from their region and you want to assign this restriction for a specific duration, how this can be achieved?
Answer: Using Analytic Privileges, you can add Region attribute and values to Attribute Restrictions and Time duration is defined in Privilege validity.
Analytic Privilege can be added to the user profile in User and Roles under the Security tab.
37. What are the different methods of data replication in HANA?
Answer: SAP LT Replication SLT
SAP Data Services
Direct Extract Connection DXC
38. What system privilege is required for a user to enable him to create user and roles in HANA studio?
Answer: Only database users with the system privilege ROLE ADMIN are allowed to create users and roles in HANA studio.
39. Suppose you have the sales data in a database table in a different currency. How can you generate a Sales report for a region in a particular currency?
Answer: Create an Analytic view by selecting the table column containing the sales data and currency and perform currency conversion. Once the view is activated, we can use it to generate reports.
40. What are the factors that affect currency conversion?
Answer: Currency conversion is performed based on source currency, target currency, exchange rate, and date of conversion. You can select a currency from the attribute data used in the view. Currency conversion is enabled for Analytic view and Calculation views.
41. What is the prerequisite for doing the currency conversion?
Answer: You need to import tables TCURC, TCURF, TCURN, TCURR, TCURT, TCURV, TCURW, and TCURX.
42. What are the different privilege types that can be assigned to a user in HANA studio?
- System Privilege
- Object Privilege
- Analytic Privilege
- Package Privilege
- Application Privilege
- Privilege on roles
43. How you can connect SAP HANA to Microsoft Excel?
Answer: MDX Provider is used to connecting MS Excel to SAP HANA database system. It provides a driver to connect the HANA system to Excel and is further used for data modeling. You can use Microsoft Office Excel 2010/2013 for connectivity with HANA for both 32 bit and 64 bit Windows.
44. What is a different recovery mechanism can be performed in the HANA system?
Answer: Most Recent State − Used for recovering the database to the time as close as possible to the current time. For this recovery, the data backup and log backup have to be available since the last data backup and log area are required to perform the above type recovery.
The point in Time − Used for recovering the database to a specific point in time. For this recovery, the data backup and log backup have to be available since the last data backup and log area are required to perform the above type recovery.
Specific Data Backup − Used for recovering the database to a specified data backup. Specific data backup is required for the above type of recovery option.
Specific Log Position − This recovery type is an advanced option that can be used in exceptional cases where a previous recovery failed.
45. Name the operating system SAP HANA supports?
Answer: More than 70% of customers run their SAP workloads on Linux with the use of SUSE Linux Enterprise Server, which is the best OS choice for SAP HANA.
46. Does HANA/IMDB replace Oracle?
Answer: Once the Business Suite keeps running on IMDB, Oracle won’t be required anymore by SAP clients who purchase HANA. This doesn’t affect anything in the short term because those people buying HANA today will still need an Oracle ERP system.
47. Explain Parallel Processing in SAP HANA?
Answer: Using the columnar data storage approach, the workload in SAP HANA is divided vertically. The columnar approach allows linear searching and aggregation of data rather than a two-dimensional data structure. If more than one column is to be processed, each task is assigned to the diverse processor. Operations on one column are then collimated by column divisions processed by different processors.
48. What does HANA cost?
Answer: SAP hasn’t completely affirmed HANA permitting costs yet the equipment is someplace around $1-200k for every TB. Add to this permitting costs which are as yet being made on a for every client premise.
49. What are the different license keys type in HANA system? What is their validity?
Answer: Temporary License key
Permanent License Key
Temporary License keys are automatically installed when you install the HANA database. These keys are valid only for 90 days and you should request permanent license keys from SAP market place before the expiry of this 90 days period after installation.
Permanent License keys are valid till the predefined expiration date. License keys specify the amount of memory licensed to target HANA installation.
50. What happens to my data when I shut down the SAP HANA One instance?
Answer: The SAP HANA One instances are backed up by persistent data stores and volumes and will remain attached until the user terminates the instance. Once the instance is terminated, by default, only the root volume is deleted. The data, log, and backup volumes are not deleted automatically. Those volumes can be attached to other instances if required. If the instance is not needed anymore, make sure to delete all the EBS volumes to avoid storage charges for unused EBS volumes.