Stop using CTEs just to filter window functions.

📰 Medium · Data Science

Learn to optimize SQL queries by avoiding unnecessary use of Common Table Expressions (CTEs) for filtering window functions, improving performance and readability

intermediate Published 3 Jul 2026
Action Steps
  1. Identify queries using CTEs for filtering window functions
  2. Replace CTEs with derived tables or subqueries to simplify queries
  3. Use window functions directly in the SELECT clause to filter results
  4. Test and compare query performance before and after optimization
  5. Apply this technique to existing queries to improve overall database efficiency
Who Needs to Know This

Data scientists and data analysts can benefit from this knowledge to write more efficient SQL queries, while data engineers can apply these principles to optimize database performance

Key Insight

💡 CTEs are not necessary for filtering window functions and can be replaced with more efficient methods

Share This
💡 Simplify your SQL queries by avoiding unnecessary CTEs for window functions!

Key Takeaways

Learn to optimize SQL queries by avoiding unnecessary use of Common Table Expressions (CTEs) for filtering window functions, improving performance and readability

Full Article

If you’ve ever written a Query like this just to get the top record per category: Continue reading on Medium »
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