Backend Developer
mediumn-plus-one-problem
What is the N+1 query problem and how do you fix it?
Answer
N+1 happens when you fetch a list (1 query) and then fetch related data per item (N queries).
**Fixes:**
- Use joins or eager loading
- Batch queries (IN clause)
- Add caching for repeated lookups
**Interview tip:** mention ORMs often hide this problem; profiling and query logging are essential.
Related Topics
DatabasesPerformanceORM