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How do you handle schema evolution in data lakes or data warehouses?

SQLeasy0.3 min readPremium
Frequency
Low
Asked at 1 company
Category
487
questions in SQL
Difficulty Split
130E|271M|86H
in this category
Total Bank
1,863
across 7 categories
Asked at these companies
American Express
Expert AnswerPremium
51 wordsInterview-ready
**Strategies**: (1) Schema-on-read (Parquet, JSON)—flexible; add columns at read. (2) Additive evolution—add column with default; deprecated columns ignored. (3) Schema registry (Avro)—compatibility checks. (4) Versioned datasets (v1, v2)—backfill or dual-read. **Best practice**: Additive preferred; avoid breaking changes; compatibility mode (backward/forward). **Backfill**: New columns; backfill historical or NULL....
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