What are some techniques for optimizing Django ORM queries?

What are some techniques for optimizing Django ORM queries?

There are several techniques to optimize Django ORM queries, such as using select_related and prefetch_related to reduce the number of queries, filtering data at the database level, and using values() or values_list() to retrieve only the necessary fields.

Can you explain how select_related works?

Sure! The select_related method is used for single-valued relationships (like ForeignKey). It performs a SQL join and includes the fields of the related object in the same query, which reduces the number of database hits.

What about prefetch_related?

Prefetch_related is used for multi-valued relationships (like ManyToMany). It executes a separate query for the related objects and does the 'joining' in Python, which is efficient for fetching related data.

Are there any other best practices I should follow?

Yes! Always use the Django Debug Toolbar to analyze your queries, avoid using .count() on large querysets, and consider using database indexes for frequently queried fields.