🔧 Advanced SQL Interview Questions
Master window functions, CTEs, stored procedures, triggers, and JSON operations
Window functions, CTEs, stored procedures, triggers, and JSON operations
Explain Window Functions in SQL
HardWindow functions perform calculations across a set of rows related to the current row, without grouping them into a single output row like aggregate functions.
Explain CTEs and Recursive Queries
HardCommon Table Expressions (CTEs) define temporary named result sets. Recursive CTEs can reference themselves, useful for hierarchical data.
What is the difference between Stored Procedures and Functions?
MediumStored procedures and functions are both database objects containing SQL logic, but they differ in usage, return values, and capabilities.
Explain Database Triggers and their use cases
MediumTriggers are database objects that automatically execute in response to specific events (INSERT, UPDATE, DELETE) on a table.
How to work with JSON data in databases?
MediumModern databases support JSON data types and functions for querying, indexing, and manipulating semi-structured data.
Advanced SQL Interview Tips
- ✓ Master window functions (ROW_NUMBER, RANK, LAG, LEAD)
- ✓ Know how to write recursive CTEs for hierarchical data
- ✓ Understand when to use stored procedures vs functions
- ✓ Be familiar with trigger use cases and best practices
- ✓ Know JSON operations in PostgreSQL and MySQL
- ✓ Understand the performance implications of complex queries
- ✓ Practice writing queries without looking at documentation
- ✓ Know how to optimize window function queries