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REPARTITION vs COALESCE for managing partitions

SQLmedium0.4 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
Myntra
Key Concepts Tested
partition
Expert AnswerPremium
77 wordsInterview-ready
REPARTITION: full shuffle; creates N partitions; use when changing partition count or key. COALESCE: reduces partitions without full shuffle; combines partitions; use before writes to reduce output files. repartition(200) vs coalesce(50): repartition spreads data; coalesce merges. Use coalesce when reducing; repartition when increasing or changing key. **Why it matters**: Design choices compound at scale—wrong approach can cause 100× overhead....
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