Latest SAP HANA Interview Questions and Answers
What is SAP HANA?
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.
Mention the two types of Relational Data stored in HANA?
The two types of relational data stored in HANA includes
- Row Store
- Column Store
What is the role of the persistence layer in SAP HANA?
SAP HANA has an in-memory computing engine and access the data straightaway without any backup. To avoid the risk of losing data in case of hardware failure or power cutoff, persistence layer comes as a savior and stores all the data in the hard drive which is not volatile.
What is modeling studio?
Modeling studio in HANA performs multiple task like
- Declares which tables are stored in HANA, first part is to get the meta-data and then schedule data replication jobs
- Manage Data Services to enter the data from SAP Business Warehouse and other systems
- Manage ERP instances connection, the current release does not support connecting to several ERP instances
- Use data services for the modeling
- Do modeling in HANA itself
- essential licenses for SAP BO data services
What are the different compression techniques?
There are three different compression techniques
- Run-length encoding
- Cluster encoding
- Dictionary encoding
What is latency?
Latency is referred to the length of time to replicate data from the source system to the target system.
Explain what is transformation rules?
Transformation rule is the rule specified in the advanced replication setting transaction for the source table such that data is transformed during the replication process.
What is the advantage of SLT replication?
- SAP SLT works on trigger based approach; such 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.
Explain how you can avoid un-necessary information from being stored?
To avoid un-necessary information from being stored, you have to pause the replication by stopping the schema-related jobs
What is the role of master controller job in SAP HANA?
The job is arranged on demand and is responsible for
- Creating database triggers and logging table into the source system
- Creating Synonyms
- Writing new entries in admin tables in SLT server when a table is replicated/loaded
Explain what happens if the replication is suspended for a longer period of time or system outage of SLT or HANA system?
If the replication is suspended for a longer period of time, the size of the logging tables increases.
What is the role of the transaction manager and session?
The transaction manager co-ordinates database transactions and keeps a record of running and closed transactions. When transaction is rolled back or committed, the transaction manager notifies the involved storage engines about the event so they can run necessary actions.
Explain how you can avoid un-necessary logging information from being stored?
You can avoid un-necessary logging information from being stored by pausing the replication by stopping the schema-related jobs.
Explain how SQL statement is processed?
In the HANA database, each SQL statement is implemented in the reference of the transaction. New session is allotted to a new transaction.
Name various components of SAP HANA?
- SAP HANA DB
- SAP HANA Studio
- SAP HANA Appliance
- SAP HANA Application Cloud