UNION vs UNION ALL in SQL: What’s the Difference and When to Use Each
The difference between UNION and UNION ALL in SQL is mainly about duplicates and performance. Here’s the breakdown 👇 Feature UNION UNION ALL Duplicates Removes duplicate rows from the result set. Keeps all duplicates (does not remove them). Performance Slower, because SQL has to check and remove duplicates using DISTINCT. Faster, because it simply combines…