🔧 Advanced SQL Interview Questions
Master window functions, CTEs, stored procedures, triggers, and JSON operations
Window functions, CTEs, stored procedures, triggers, and JSON operations
Window functions perform calculations across a set of rows related to the current row, without grouping them into a single output row like aggregate functions.
Common Table Expressions (CTEs) define temporary named result sets. Recursive CTEs can reference themselves, useful for hierarchical data.
Stored procedures and functions are both database objects containing SQL logic, but they differ in usage, return values, and capabilities.
Triggers are database objects that automatically execute in response to specific events (INSERT, UPDATE, DELETE) on a table.
Modern 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