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Module 30: BW/4HANA Interview Preparation (BW/4HANA 2.0)

This module prepares you for real BW/4HANA interviews, not just theoretical exams.
Questions are grouped by topic + scenario, with expected senior-level answers.

1. BW/4HANA Fundamentals – Core Questions​

Q1. What is BW/4HANA and why was it introduced?​

Expected Answer:
BW/4HANA is SAP's next-generation data warehouse built exclusively on SAP HANA.
It was introduced to leverage in-memory processing, pushdown, simplified data models, and real-time analytics, while removing legacy BW limitations like aggregates and InfoCubes.

Q2. BW on HANA vs BW/4HANA?​

AspectBW on HANABW/4HANA
CompatibilityBackward compatibleNot backward compatible
InfoCubesSupportedRemoved
ModelsMixedSimplified
PushdownPartialPushdown-first

Q3. What is LSA++?​

Answer:
LSA++ is a layered scalable architecture that separates data acquisition, harmonization, and consumption, optimized for HANA pushdown and reuse.

2. aDSO & CompositeProvider Questions​

Q4. What are the different types of aDSOs in BW/4HANA 2.0?​

Expected Answer (Key Points):

  • Standard aDSO (Reporting & harmonization)
  • Write-optimized aDSO (Fast ingestion)
  • Planning aDSO (Write-back)
  • Data mart aDSO (Consumption)
  • Corporate memory aDSO (History)

👉 Mention table behavior (inbound / active / changelog).

Q5. aDSO vs InfoCube?​

Answer:
aDSOs replace InfoCubes and DSOs by combining flexibility, delta handling, and simplified table structures without aggregates.

Q6. CompositeProvider vs MultiProvider?​

Answer:
CompositeProviders support HANA pushdown, real-time joins, and federation, whereas MultiProviders were static and performance-limited.

Scenario Question​

Q7. Would you build one CompositeProvider per query?

Correct Answer:
No. CompositeProviders should be reusable semantic layers, not query-specific objects.

3. Delta & Performance Scenarios (Very Important)​

Q8. Explain delta handling in BW/4HANA.​

Answer:
Delta handling is source-driven, managed via ODP, stored in aDSO change logs, and propagated downstream without full reloads.

Q9. A delta load is broken in production. What will you do?​

Expected Flow:

  1. Check delta queue
  2. Analyze last successful request
  3. Validate aDSO change log
  4. Fix root cause
  5. Avoid re-init unless unavoidable

Q10. Why is ODP important?​

Answer:
ODP provides a stable, unified delta framework across SAP systems and is mandatory for future-proof BW/4HANA integration.

4. HANA Pushdown & Performance Questions​

Q11. What is HANA pushdown?​

Answer:
Executing data-intensive logic directly in HANA instead of ABAP to leverage parallelism, in-memory processing, and set-based operations.

Q12. ABAP routine vs AMDP?​

AspectABAP RoutineAMDP
ExecutionApp serverHANA DB
ProcessingRow-basedSet-based
PerformanceSlowerFaster
StrategyLegacyStrategic

Scenario Question​

Q13. A query is slow even on HANA. What will you check first?

Correct Answer:

  • Data model
  • CompositeProvider joins
  • Filters & pruning
  • HANA execution plan
    👉 Not hardware

5. CDS vs BW Questions (Frequently Asked)​

Q14. Can CDS replace BW?​

Correct Answer:
No. CDS is ideal for operational and embedded analytics, while BW is required for enterprise-scale, historical, governed analytics.

Q15. When would you use CDS instead of BW objects?​

Answer:
When:

  • Real-time operational reporting is required
  • No historical persistence is needed
  • Data volume is manageable
  • Embedded analytics in S/4HANA

Q16. Can BW queries run on CDS views?​

Answer:
Yes, via Open ODS Views, but BW semantics and authorizations still apply.

6. Tricky / Trap Interview Questions​

Q17. Should everything be virtualized in BW/4HANA?​

Correct Answer:
No. Virtualize for agility and real-time access, but persist data when history, performance stability, or delta propagation is required.

Q18. Is FOX obsolete?​

Correct Answer:
FOX is functional but AMDP-based planning is preferred for performance and scalability.

Q19. Are aggregates required in BW/4HANA?​

Answer:
No. Aggregates are obsolete due to HANA's runtime aggregation capabilities.

7. One-Liners for Interviews (High Impact)​

Interview Power Lines
  • "BW/4HANA performance issues are design issues, not hardware issues."
  • "Persist facts, virtualize semantics."
  • "Queries should explain data, not compute it."
  • "Pushdown is a design principle, not an optimization."

8. Mock Scenario Question (Architect Level)​

Q20. Design a BW/4HANA solution for S/4 sales analytics.

Expected Answer Outline:

  • ODP extraction from S/4
  • Staging aDSO
  • Harmonized Standard aDSO
  • CompositeProvider for reporting
  • BW Queries consumed in SAC (Live)

9. Final Interview Checklist​

Before Interview
  • Be clear on aDSO types
  • Understand ODP & delta
  • Know pushdown vs ABAP
  • Have one real project story

10. Summary​

  • Interviews focus on design decisions
  • Scenario questions matter more than definitions
  • Pushdown & performance are central
  • CDS complements BW, does not replace it
  • Real-world thinking wins interviews
Learning Tip

Interviews reward depth of understanding, not breadth of keywords.