SQL Anti-Patterns You Should Avoid
a day ago
- #Best Practices
- #SQL
- #Database Optimization
- Mishandling Excessive Case When Statements: Large CASE WHEN logic in views creates inconsistency; use dimension tables instead.
- Using Functions on Indexed Columns: Avoid functions on indexed columns to prevent full table scans; adjust queries or create indexed computed columns.
- Using SELECT * In Views: SELECT * in views can break with schema changes and pull unnecessary data; specify columns explicitly.
- Overusing DISTINCT to 'Fix' Duplicates: DISTINCT masks join issues; fix the underlying join logic instead.
- Excessive View Layer Stacking: Layering views slows performance and complicates debugging; flatten transformations periodically.
- Nested Subqueries That Do Too Much: Deeply nested subqueries are hard to debug; use CTEs for better readability.