Tata Consultancy Services Interview Question

SQL & Database What is the difference between INNER JOIN and LEFT JOIN? How do you find duplicate records in a table? Explain window functions with an example. Difference between DELETE, TRUNCATE, and DROP. How do you optimize a slow-running SQL query? What is normalization vs denormalization? 🔹 Data Warehousing What is a fact table and dimension table? Explain SCD Type 1 vs Type 2 with example. What is a star schema? What is ETL and how is it different from ELT? What is data granularity?