// Slow: Fetches entire entities, forces dirty checking List<Post> posts = entityManager.createQuery("select p from Post p", Post.class).getResultList(); High-performance code does this:
If you have typed "high-performance java persistence book pdf" into Google, you belong to a specific tribe of developer. You are not a beginner. You have already felt the sting of a N+1 query in production. You have watched a seemingly simple @OneToMany annotation bring a microservice to its knees. high-performance java persistence book pdf
The high-performance secret? Instead of updating item.current_price , you append a bid to a separate bid_history table and calculate the price on the fly via a materialized view. You bypass the lock entirely. // Slow: Fetches entire entities, forces dirty checking
Here is the uncomfortable truth:
But don't close the tab. Because the real high-performance persistence isn't about the file format. It is about three counter-intuitive truths that most developers learn too late. The search for the "PDF" usually starts after a developer realizes that Hibernate generated 500 queries for a single REST call. The knee-jerk reaction is to abandon ORMs entirely. You have watched a seemingly simple @OneToMany annotation