SAP HANA Interview Questions You'll Most Likely Be Asked

By Vibrant Publishers

• 270 SAP HANA Interview Questions
• 75 HR Interview Questions 
• Real life scenario based questions
• Strategies to respond to interview questions
• 2 Aptitude Tests

SAP HANA Interview Questions

• Language: English
• Publisher: Vibrant Publishers
• Release date: Jul 18, 2017
• ISBN: 9781946383730

Book preview

SAP HANA

Interview Questions

You'll Most Likely Be Asked

Job Interview Questions Series

www.vibrantpublishers.com

*****

SAP HANA Interview Questions You'll Most Likely Be Asked

Copyright 2021, By Vibrant Publishers, USA. All rights reserved. No part of this publication may be reproduced or distributed in any form or by any means, or stored in a database or retrieval system, without the prior permission of the publisher.

This publication is designed to provide accurate and authoritative information in regard to the subject matter covered. The author has made every effort in the preparation of this book to ensure the accuracy of the information. However, information in this book is sold without warranty either expressed or implied. The Author or the Publisher will not be liable for any damages caused or alleged to be caused either directly or indirectly by this book.

Vibrant Publishers books are available at special quantity discount for sales promotions, or for use in corporate training programs. For more information please write to [e-mail]

Please email feedback / corrections (technical, grammatical or spelling) to [e-mail]

To access the complete catalogue of Vibrant Publishers, visit www.vibrantpublishers.com

*****

Table of Contents

1. General Overview

2. Architecture

3. Data Provisioning

4. Modeling

5. Security and Authorization

6 Reporting

7. Backup and Recovery

8. Pricing and Licensing

9. Predictive Analysis on HANA

HR Questions

INDEX

*****

SAP HANA Interview

Questions

Review these typical interview questions and think about how you would answer them. Read the answers listed; you will find best possible answers along with strategies and suggestions.

*****

General Overview

1: What led to the invention of SAP HANA technology?

Answer:

The following led to the invention of SAP HANA technology:

a) Information explosion where data was growing massively from Gigabytes to Terabytes to Petabytes and business required analytics based on this enormous data

b) Instant data access anytime and anywhere became the customer need to make real time decisions

c) Business required a flexible way to analyze current and historic information for various reporting solutions

2: Which technologies did SAP HANA evolve from?

Answer:

SAP HANA evolved by combining earlier developed technologies, BW Accelerator and Max DB with its in-memory capabilities.

3: What are the main components in SAP HANA?

Answer:

The main components of SAP HANA are:

a) SAP In-Memory Database (IMDB)

b) In-Memory Computing Studio and

c) Data Replication components (SLT, BODS, etc.)

4: What is SAP HANA?

Answer:

SAP HANA is an in-memory technology supported by column-based storage and high data compression that allows processing of massive volumes of data and high speed business reporting. It allows its customers to explore and analyze huge volumes of data from any data source in real time with unprecedented performance. In comparison to traditional RDBMS systems, it is much simpler and faster.

5: What are the capabilities and benefits that HANA offers?

Answer:

a) Real Time data

b) Faster queries on large volumes of data

c) Flexible modeling

d) Minimized data duplication

e) No aggregate tables

6: What are the basic technology concepts in SAP HANA?

Answer:

The basic technology concepts in SAP HANA are:

a) In-Memory where data resides on main memory than on disk

b) Colum based database, Data Compression and Pushing application logic to the database layer

c) Parallel processing and multi-core CPUs leveraging the new hardware technology

7: What is the benefit of In-Memory in SAP HANA?

Answer:

The main benefit of using in-memory database is that accessing data from main memory is much faster than accessing data on disk. A very high-speed bus connects the main memory directly to the processors, whereas in hard disks a chain of buses and controllers are involved.

8: What is columnar storage and how does it support faster access of data?

Answer:

Columnar database stores data in a sequence of columns; the entries of a column get stored in contiguous memory locations. This phenomenon is called columnar storage.

Column store is optimized for READ; only the selected columns will be read during query processing, hence it performs well. It offers significant advantages of data compression or encoding data into fewer bits allowing larger volumes of data in main memory and higher performance in selection and aggregation queries.

9: Are column-based tables always better than row-based tables?

Answer:

No. There are business cases where row based tables are advantageous over column, like in frequently updated databases. If the database is frequently updated or inserted, row-based tables perform faster as they are optimized for write operations.

10: What is the difference between row store and column store?

Answer:

The row store is optimized for WRITE operations and is easy to insert/update. All data has to be read during selection, even if only a few columns are involved in the selection process.

Compared to this, the column store is optimized for performance of READ operations and do not support easy insert/update. After selection, selected rows have to be reconstructed from columns.

11: Can you have row store tables in SAP HANA?

Answer:

HANA can have column or row stores; there is no technical limitation. If you have row-store table in HANA, you cannot create any column views on top of those tables. Typically, Metadata or rarely accessed data is stored in a row-store format.

12: How does insert or update work faster in HANA environment?

Answer:

SAP HANA do not write directly into column store tables while inserting or updating the data as column store is not optimized for write operations. It first writes the data into a row store buffer which is write-optimized and hence faster. It then takes that data, restructures it and pushes it into a column-oriented store. As a final step, it pushes this restructured columnar data into the main column-oriented table. By following this process, SAP HANA makes use of the row store for write operations to ensure faster performance.

13: What degree of data compression is expected in SAP HANA?

Answer:

The degree of data compression depends on the number of unique values in the data; the fewer the unique values, the better the data compression.

14: What is Delta Merge and how does it support faster read operations?

Answer:

Delta merge moves the data from WRITE optimized Delta memory to READ optimized and compressed Main memory. It transforms the data into an optimized format in terms of memory consumption and read performance. By merging the data into the main storage which is column store, read operations would be faster.

15: What are the different ways of performing delta merge operation?

Answer:

Delta Merge can be done automatically by using Smart Merge technology or manually using MERGE DELTA OF function in SQL statement or using right click option in HANA studio.

16: What is memory latency and how does it hit the performance?

Answer:

While executing any application logic on the data, the application has to get the data from the database, process it, and possibly send it back to the database to store the results. Sending data back and forth between the database and the application usually involves communication overhead and is limited by the speed and throughput of the network, this is memory latency.

17: How does SAP HANA handle the latency problem?

Answer:

In SAP HANA,