Tuning Spring Petclinic JPA and Hibernate configuration with Hypersistence Optimizer
Introduction In this article, we are going to see how we can tune the performance of the Spring Petclinic application using Hypersistence Optimizer. Now, while you can manually analyze your data access layer to make sure that JPA and Hibernate are properly configured, it’s much better if you can automate this task. That’s because new entities might be mapped in the future, and you want to make sure that the same performance-specific rules are consistently applied on every commit. Hypersistence Optimizer allows you to automatically detect JPA and Hibernate issues during development,… Read More
How to intercept and modify SQL queries with the Hibernate StatementInspector
Introduction A very useful, yet lesser-known, Hibernate feature is the ability to intercept and modify any auto-generated SQL statement using the Hibernate StatementInspector utility. In this article, we are going to see how the Hibernate StatementInspector mechanism works.
How to detect HHH000104 issues with hibernate.query.fail_on_pagination_over_collection_fetch
Introduction Recently, I noticed the hibernate.query.fail_on_pagination_over_collection_fetch configuration property that was introduced in Hibernate 5.2, and I had absolutely no idea it can be used to prevent the HHH000104 Hibernate issues. As previously explained, if you want to overcome the “HHH000104: firstResult/maxResults specified with collection fetch; applying in memory!” issue, you have to either use 2 queries or a window function to fetch and limit the number of parent records while making sure you always fetch all their associated child entities. Even if the HHH000104 issue is logged as a warning message, it… Read More
How to expose Hibernate Statistics via JMX
Introduction As already explained, Hibernate provides a very flexible statistics mechanism. The Hibernate metrics can be accessed either programmatically via the org.hibernate.stat.Statistics interface or via JMX (Java Management Extensions). In this article, you are going to see how you can expose the Hibernate statistics metrics using JMX.
A beginner’s guide to Hibernate Statistics
Introduction Hibernate provides a very powerful Statistics mechanism that, unfortunately, is lesser known. In this article, we are going to see how the Hibernate Statistics mechanism works, and how you can activate. While the Hibernate Statistics mechanism is not enabled by default, you will see that many applications can benefit from using it, especially when it comes to determining cache effectiveness.
How to change the @OneToOne shared primary key column name with JPA and Hibernate
Introduction In this article, we are going to see how you can change the @OneToOne shared primary key column name when using JPA and Hibernate. This has been a recurrent theme when answering questions about Hibernate or during my High-Performance Java Persistence training. As previously explained, the one-to-one database table relationship requires the Primary Key to be shared among the parent and the child tables. Unfortunately, just adding the JPA @OneToOne annotation in the child entity does not render a true one-to-one table relationship since a separate Foreign Key column will be… Read More
Hypersistence Optimizer initial release
Introduction At the end of 2018, I got this idea of writing a tool which can automatically detect JPA and Hibernate issues by scanning your data access layer and provide you optimization tips. At the beginning of February, Thodoris Chaikalis surprised me with this Facebook comment which reinforced the idea that having such a tool would be really awesome for Java developers working with JPA and Hibernate. At the end of February, I got some time off, and I started working on it, and the reaction on social media exceeded my expectations:… Read More
Why you should avoid EXTRA Lazy Collections with Hibernate
Introduction In this article, you are going to learn why using EXTRA Lazy Collections with Hibernate is a bad idea since it can lead to N+1 query issues and cause performance problems. The reason I wanted to write this article is that I keep seeing it mentioned in StackOverflow or the Hibernate forum.
How does the entity version property work when using JPA and Hibernate
Introduction In this article, I’m going to show you how the JPA @Version entity property works when using Hibernate. The most significant benefit of adding a version property to a JPA entity is that we can prevent the lost update anomaly, therefore ensuring that data integrity is not compromised.
How do JPA persist, merge and Hibernate save, update, saveOrUpdate methods work
Introduction In this article, I’m going to show you how the JPA persist and merge work and how do they compare with the Hibernate save, update, and saveOrUpdate methods. Although you should favor the JPA-based entity state transition methods, you are going to see that the Hibernate-specific update is actually a good alternative to merge when you want to reduce the number of SQL queries being executed during a batch processing task.
