In this episode, we dive into a super common performance issue in Laravel apps—known as the N+1 query problem. Before moving forward in the course, we take a moment to really understand what eager loading is and why not using it properly can slow your application to a crawl as more data shows up.
We start by reusing the code from earlier in the course (listing posts and showing the user who posted each), but before fixing anything, we install the Laravel Debugbar package to see what's really happening behind the scenes. After installation, we walk through how Debugbar works and use it to monitor the queries our app runs when loading the posts page.
At first, everything looks fine—just a single query. But as soon as we add back the line that displays the user for each post, Debugbar shows our query count jumping up: now every post triggers its own database query to fetch the user! We walk through adding more posts and see the query count keep climbing, making it clear how this gets out of hand as your data grows.
We explain why this happens (the N+1 problem), look at the impact with more data, and set things up so that in the next episode, we can jump in and actually fix the issue. By the end, you’ll know what to look for, how to spot it, and be ready to see the solution in action next time.