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Django ORM: the N+1 problem

medium

`book.author.name` looks like a free attribute access and is a database round trip. Every query appears as it fires, so the count visibly tracks the row count - then switching strategy flattens it. Includes the case where only() reintroduces the bug.

Best O(1) queriesWorst O(n) queriesSpace O(n) rows

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Read the questions this explains

Django-21-25

Django - select_related vs prefetch_related, CSRF Protection, Security Best Practices, Auth vs Authorization, Password Hashing

Django-46-50

Django - Deployment (EC2, RDS, S3), JWT Auth, Debugging, N+1 Queries, Custom Middleware

DB-MySQL-11-15

Databases - Composite Index, Covering Index, EXPLAIN, Query Optimization