Скачать или смотреть SQL UNION vs UNION ALL | Full Concept, Performance, and Interview Tips

In this video, we’ll understand one of the most asked SQL interview topics — UNION vs UNION ALL — with real examples, performance insights, and best practices.

🔹 What is UNION in SQL
🔹 What is UNION ALL
🔹 Key differences between UNION and UNION ALL
🔹 Performance comparison (why UNION ALL is faster)
🔹 Important rules: same structure, data types, column order
🔹 Practical demo with Employee tables
🔹 Interview tips & real-world use cases

📘 Definition Summary:

UNION → Combines result sets and removes duplicates. #sql #powerbi #dataanlysis #powerbiinterview

UNION ALL → Combines all rows including duplicates (faster execution).


💡 Quick Tip:
Use UNION ALL when duplicates don’t matter and performance is a priority.
Use UNION when you need unique, clean results.

🎯 Perfect for:

SQL Beginners

Data Analysts

Power BI & Data Engineers preparing for interviews


📌 Tags:
#SQL #UNIONvsUNIONALL #SQLTutorial #SQLInterviewQuestions #DataAnalyst #TechPrashantSQL #LearnSQL