🚀 Databricks Tip: REPLACE vs MERGE

When updating Delta tables, you’ve got two powerful options:

🔹 REPLACE TABLE … ON
📚 Like throwing away the entire library and rebuilding it.
- Drops the old table & recreates it.
- Schema + data = fully replaced.
- ⚡ Super fast but destructive (old data gone).
- ✅ Best for full refreshes or schema changes.

🔹 MERGE
📖 Like updating only the books that changed.
- Works row by row.
- Updates, inserts, or deletes specific records.
- 🔍 Preserves unchanged data.
- ✅ Best for incremental updates or CDC (Change Data Capture).

⚖️ Key Difference
- REPLACE = Start fresh with a new table.
- MERGE = Surgically update rows without losing the rest.

👉 Rule of thumb:
Use REPLACE for full rebuilds,
Use MERGE for incremental upserts.

#Databricks #DeltaLake