What is Change Data Capture (CDC)?
Change Data Capture (CDC) is a mechanism that captures and processes only the data that has changed (inserts, updates, deletes) instead of reloading full datasets.
It enables:
- Near real-time reporting
- Reduced data volume movement
- Better performance
- Lower system load
Real Enterprise Scenario
A company wants:
- Real-time revenue dashboard
- Updated margin every 5 minutes
- Inventory movement tracking
Full loads every hour would:
โ Overload the system
โ Increase latency
โ Slow down reporting
๐ CDC is required.
How CDC Works in SAP BDC
CDC depends on source system capability.
๐น 1๏ธโฃ CDC from SAP S/4HANA
Common approaches:
โ CDS-based delta extraction
โ ODP framework
โ Log-based capture
Changes in:
- ACDOCA
- Sales orders
- Material movements
Are captured incrementally and pushed to BDC.
๐น 2๏ธโฃ CDC from SAP ECC
Since ECC is older:
โ ODP extractors with delta queue
โ SLT (log-based table replication)
SLT reads database logs and replicates changes in near real-time.
๐น 3๏ธโฃ Ingestion into BDC
CDC data flows into:
- Managed data foundation
- Incremental processing pipelines
- Partitioned storage
Deletes and updates are handled via:
- Merge strategies
- Upsert logic
- Timestamp-based reconciliation
CDC Architecture Flow
S/4HANA / ECC โ Delta Capture (CDS / ODP / SLT) โ Change Log Processing โ BDC Incremental Load โ Semantic Layer Update โ SAC / AI / Reporting
Common CDC Interview Questions
What happens if delta queue fails?
Answer:
- Perform delta re-initialization
- Validate data reconciliation
- Check source log consistency
How do you handle delete records?
Answer:
- Soft delete flag
- Change log tracking
- Merge-based reconciliation
Benefits of CDC in BDC
โ Near real-time analytics
โ Lower network load
โ Reduced storage consumption
โ Faster dashboard refresh
โ Better scalability
Performance Considerations
- Partition by time
- Avoid excessive micro-batching
- Monitor delta queue size
- Implement proper error handling
๐ฅ 30-Second Interview Answer
In SAP Business Data Cloud, Change Data Capture enables incremental data replication from source systems like S/4HANA and ECC using CDS-based delta extraction, ODP, or SLT mechanisms. It ensures near real-time analytics while reducing system load and improving performance compared to full data loads.
You can also checkout ebooks for SAP BDC – Quick Revision – using the link :
Part 1 : https://topmate.io/vartika_gupta11/1954785
Part 2 : https://topmate.io/vartika_gupta11/1956232
Also can schedule a mock interview either by me or my team at topmate for SAP BDC – 35+ Minutes : https://topmate.io/vartika_gupta11/1962923
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