Sometimes, the Django ORM can generate inefficient SQL code. There are several optimization patterns to improve this, as follows:
- Reduce database hits with select_related: If you are using a OneToOneField or a Foreign key relationship, in forwarding direction, for a large number of objects, then select_related() can perform a SQL join and reduce the number of database hits.
- Reduce database hits with prefetch_related: For accessing a ManyToManyField method or, a Foreign key relation, in reverse direction, or a Foreign key relation in a large number of objects, consider using prefetch_related to reduce the number of database hits.
- Fetch only needed fields with values or values_list: You can save time and memory usage by limiting queries ...
