SAP HANA Interview Questions and Answers for Freshers
Question.1 What are the advantages of column-based tables?
Faster Data Access: Only affected columns have to be read during the selection process of a query. Any of the columns can serve as an index.
Better Compression: Columnar data storage allows highly efficient compression because the majority of the columns contain only a few distinct values (compared to number of rows).
Better parallel Processing: 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.
Question.2 In HANA which type of tables should be preferred – Row-based or Column-based?
Answer: SQL queries involving aggregation functions take a lot of time on huge amounts of data because every single row is touched to collect the data for the query response. In columnar tables, this information is stored physically next to each other, significantly increasing the speed of certain data queries. Data is also compressed, enabling shorter loading times.
Conclusion: To enable fast on-the-fly aggregations, ad-hoc reporting, and to benefit from compression mechanisms it is recommended that transaction data is stored in a column- based table. The SAP HANA data-base allows joining row-based tables with column-based tables. However, it is more efficient to join tables that are located in the same row or column store. For example, master data that is frequently joined with transaction data should also be stored in column-based tables.
Few more important points about column table:
1. HANA modeling views are only possible for column tables. Row based tables cannot be used in modeling views.
2. For that reason, Replication Server creates SAP HANA tables in column store by default.
3. Data Services also creates target tables in column store as default for SAP HANA database
4. The SQL command to create column table: “CREATE COLUMN TABLE Table_Name..”.
5. The data storage type of a table can be modified from Row to Column storage with the SQL command “ALTER TABLE Table_Name COLUMN“.
Question.3 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 Simplified application logic Higher level of concurrency.
Question.4 How does SAP HANA support Massively Parallel Processing?
Answer: With an 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.
Question.5 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 hours to get the data ready for analysis.
Question.6 What is the SAP HANA platform?
Answer: SAP HANA is an in-memory data platform that is deployable as an on-premise appliance or in the cloud. It is a revolutionary platform that’s best suited for performing real-time analytics and now real-time transactions, but also for developing and deploying real-time applications. At the core of this real-time data platform is the SAP HANA database, which is fundamentally different from any other database engine in the market today.
Question.7 When new version of SAP CRM was launched?
Answer: In November 2012, SAP launched the SAP 360 Customer solution. With SAP CRM powered by SAP HANA as the backbone, this solution delivers an unparalleled offering for customer relationship management leveraging the power of new technologies including mobile, in-memory and cloud.
Question.8 What are the version of SAP Business Suite? Do we need to be on in order to migrate our database to SAP HANA?
Answer: The solution comes as a new enhancement package. Therefore, you need to move
SAP ERP to:
• SAP ERP 6.0 enhancement package 6
• SAP CRM 7.0 enhancement package 2
• SAP SCM 7.0 enhancement package 2.
Question.9 What does this announcement mean for the role of SAP NetWeaver BW going forward?
Answer: SAP HANA Analytics Foundation for SAP Business Suite and SAP NetWeaver BW powered by SAP HANA complement each other. Together they cover all analytic use cases on one data source. SAP HANA Analytics Foundation provides operational reporting and analytics capability directly on the original transactional data, whereas SAP NetWeaver BW empowers strategic and tactical analytics scenarios with complex logic, sophisticated key performance indicators (KPIs) and benchmarking.
Question.10 Does this announcement mean that in future, SAP Business Suite will only run on SAP HANA or only on SAP databases?
Answer: No. SAP Business Suite is, and will remain, database-agnostic. Staying true to the principles of “innovation without disruption and open choices to customers,” SAP gives customers a choice. We continue to support the existing databases a customer may have licensed from SAP for use with SAP Business Suite applications, and allow complete or partial licensing of SAP HANA.
Question.11 Can I run SAP Business Suite on SAP HANA One on Amazon?
Answer: No. SAP Business Suite does not run on SAP HANA One. SAP Business Suite powered by SAP HANA is currently optimized to run on premise and not on SAP HANA One on Amazon.
Question.12 Once the database of SAP Business Suite applications is migrated to SAP HANA, do we still need any additional databases?
Answer: No. Once SAP HANA becomes the database for an SAP Business Suite application, you will not need any other database for that purpose.
Question.13 What do you mean by In- Memory?
Answer: “An in-memory database is a database management system that primarily relies on main memory for computer data storage”. It resides in a computer’s random access memory (RAM), as opposed to querying data that is stored on physical disks. Allowing business intelligence (BI) and analytic applications to support faster business decisions. In addition to providing an incredibly fast query response times, in-memory analytics can reduce or eliminate the need for data indexing and storing pre-aggregated.
Question.14 What is HANA?
Answer: HANA has been called variously an acronym for HAsso’s New Architecture (a reference to SAP founder Hasso Plattner). HANA is a pre-packaged and pre-configured appliance that is ready to run the in-memory database on a multi-core processor hardware with terabytes of memory. It is an Analytic Appliance In-memory SAP Software + Special Hardware HANA is a database technology SQL and MDX interfaces, relational stores etc. HANA is a platform, One platform for transactions and analysis.
Question.15 For what we use ‘Migrate’ from Quick launch?
Answer: Multi lingual
Question.16 Why we need Security & Authorization of SAP HANA? What does it maintain?
Answer: Control access to objects/views
Restrict users from viewing Information models.
Question.17 Which calendar types can be created for Time Attribute views?
Answer: Gregorian calendar and Fiscal calendar.
Question.18 What are the features of HANA optimized Infocubes?
Answer: No dimension tables, No secondary fact-table, They represent “flat structures.
Question.19 What does Calculation engine performs?
Answer: Create joins at run-time, Create calculated measures & calculated attributes, Compute & executes Calculation Views.
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