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How would you add columns to a table without impacting queries?

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
Capco
Expert AnswerPremium
57 wordsInterview-ready
**Add with default**: ALTER TABLE t ADD COLUMN new_col INT DEFAULT 0; existing rows get default; no full scan in most systems. **Add at end**: Avoids rewriting. **NOT NULL**: May require backfill; add as nullable first, backfill, then alter to NOT NULL. **Backfill**: In batches if default not sufficient....
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