Microsoft Lakehouse Delta Table Logging

hi, Fabric Lakehouse does not perform automatic change detection across all columns. 

A robust ingestion pattern requires defining one or more keys that uniquely identify a record (cust_num + RecordDate in your case).

If the business expects column-by-column change detection, that must be implemented in your ingestion pipeline (e.g., by hashing all columns or comparing snapshots via CDF).

Best practices 

1. Continue using MERGE with well-defined keys.
2. If you want “all column” change detection, add a row hash column (MD5/SHA of all fields) and compare hashes during ingestion.
3. Use CDF for incremental extraction instead of time-window-based logic (this avoids reintroducing duplicates).

Fabric Lakehouse Delta tables don’t auto-detect all column changes.

CDF gives raw inserts/updates/deletes, but won’t auto-merge.

MERGE always needs defined keys (like cust_num) and explicit update rules.

“All-column automatic change detection” is not supported out-of-the-box—must be coded manually.
👉 Best practice: use CDF + MERGE with business keys.