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You are planning schema evolution where columns may be added and reordered. You want reliable column mapping for long‑term merges. Which setting is appropriate?

🟡 Medium Conceptual Mid level
1Times asked
May 2026Last seen
May 2026First seen

💡 Model Answer

The safest approach is to enable name‑based column mapping and automatic schema merging. Set delta.columnMapping.mode = "name" so that Delta tracks columns by their names rather than positions. Then enable spark.databricks.delta.schema.autoMerge.enabled = true to allow the engine to automatically merge new columns when you run a MERGE or INSERT. With name‑based mapping, reordering columns in the source does not break downstream queries, and auto‑merge ensures that added columns are added to the target schema without manual CTAS steps. This combination gives reliable, long‑term column mapping for evolving schemas.

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