Coding girl🤗

✅ *Core SQL Interview Questions With Answers - Part 4* 🖥️ 31 What are SQL Views - Virtual tables based on query results - Simplify complex queries - Example: CREATE VIEW high_earners AS SELECT * FROM employees WHERE salary > 50000; 32 What is a Stored Procedure - Pre-compiled SQL code block - Reusable, reduces network traffic - Example: CALL GetEmployeeReport(1001); 33 What are SQL Triggers - Auto-execute on events (INSERT, UPDATE, DELETE) - Enforce business rules automatically - Example: Trigger to log salary changes; 34 Difference between DELETE and TRUNCATE - DELETE removes specific rows, logs each - TRUNCATE removes all rows, faster, no logging - DELETE can use WHERE; TRUNCATE cannot; 35 What is ACID property - Atomicity: All or nothing - Consistency: Valid state always - Isolation: Transactions independent - Durability: Committed data persists; 36 What is Normalization - Organize data to reduce redundancy - 1NF, 2NF, 3NF levels - Example: Split customer and address tables; 37 What is Denormalization - Add redundancy for read performance - Used in data warehouses - Trade-off: faster queries vs storage; 38 What are Transactions - Group of operations as single unit - BEGIN TRANSACTION, COMMIT, ROLLBACK - Example: Bank transfer (deduct + credit); 39 What is an Index Scan vs Seek - Scan: reads entire index/table - Seek: directly finds rows (faster) - Use covering indexes for best performance; 40 Interview tip you must remember - Draw ER diagrams for relationships - Always mention when to use views vs temp tables - Practice EXPLAIN ANALYZE for query optimization *Double Tap ❤️ For Part 5*