Indexing and Query Optimization

Query Optimization Tips

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Optimization Tips

Learning Objectives

•Learn optimization techniques
•Avoid common pitfalls

Lesson Outline

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Optimization Tips

Query Optimization Tips

1. Use Indexes Effectively

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2. Avoid SELECT *

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3. Avoid Functions on Indexed Columns

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4. Use LIMIT for Large Results

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5. Prefer EXISTS over IN for Subqueries

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6. Index Strategy

Index columns used in WHERE, JOIN, ORDER BY
Composite indexes: most selective column first
Don't over-index (hurts writes)
Remove unused indexes

7. Use EXPLAIN

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