Lazy and Eager Loading

Lazy Loading real life example?

Imagine you're at a buffet. You don't pile everything on your plate at once; instead, you pick items as you need them. That's lazy loading in a nutshell. In Hibernate, this means that data is fetched from the database only when it's explicitly requested.

Lazy Loading Defined: It's a strategy where Hibernate defers the initialization of an associated object until it's needed.

Why is it Cool?

• Efficiency: It prevents loading unnecessary data, saving time and resources.
• Memory Friendly: Only fetches data when required, avoiding memory bloat.

But...

Overusing lazy loading can lead to the “N+1 selects problem,” where the app makes numerous small database calls, potentially impacting performance.

Eager Loading real life example?

Back to the buffet analogy: eager loading is like filling your plate with everything all at once. In Hibernate terms, this means fetching the main entity and all its related entities from the database in one go.

Eager Loading Defined: A strategy where Hibernate loads the main entity and its associated entities simultaneously.

Why Opt for Eager Loading?

• Immediate Access: Everything you need is loaded and ready to use.
• Solves N+1 Problem: No extra queries for associated entities.

Butt...

It can be overkill, loading data you might not need, thus affecting performance and memory usage.

Putting It into Practice

In Hibernate, these fetching strategies are not just theoretical concepts. You can implement them using annotations like @OneToMany(fetch = FetchType.LAZY) or @OneToMany(fetch = FetchType.EAGER). It's like choosing your strategy at the start of a chess game.

Best Practices: Making the Right Move

• Know Your Needs: Like a chef choosing ingredients, select the fetching strategy that suits your application's taste.
• Start with Lazy: When in doubt, start lazy. It's easier on resources.
• Keep an Eye Out: Monitor application performance. If something's amiss, reevaluate your fetching strategy.