What is eager loading and how does it work in different programming languages?

What is eager loading and how does it work in different programming languages?

Eager loading is a design pattern used to load related data at the same time as the main data. In languages like Ruby on Rails, it preloads associations to avoid N+1 query problems. In Python with SQLAlchemy, you can use the joinedload option to achieve similar results.

Can you give me an example of eager loading in Python?

Sure! In SQLAlchemy, you can use session.query(User).options(joinedload(User.posts)).all() to load users along with their posts in one query.

How does eager loading differ in Java?

In Java, particularly with Hibernate, you can use the @OneToMany(fetch = FetchType.EAGER) annotation to specify that related entities should be loaded eagerly.

Are there any downsides to using eager loading?

Yes, eager loading can lead to performance issues if too much data is loaded at once, especially if the relationships are deep or complex.