How to map multiple JPA entities to one database table with Hibernate

Introduction In this article, we are going to see how we can map multiple JPA entities to one database table with Hibernate. Using multiple entities can speed up both read and write operations. This question has been a recurring theme on StackOverflow, so I decided to explain the advantages of mapping multiple JPA entities to the same database table.

How to write JPA Criteria API queries using Codota

Introduction Writing JPA Criteria API queries is not very easy. The Codota IDE plugin can guide you on how to write such queries, which greatly simplifies the process. In this article, we are going to see how Codota works and how it can help you discover a given API.

How to override the default Hibernate Session FlushMode

Introduction In this article, we are going to see how we can override the default FlushMode used by Hibernate. If you bootstrap Hibernate natively, and not as a JPA provider, de default FlushMode.AUTO is used which, as explained in this article, does not trigger a Persistence Context flush prior to executing a native SQL query.

Query timeout with JPA and Hibernate

Introduction In this article, we are going to see what is the best way to set up the query timeout interval with JPA and Hibernate. Setting the query timeout allows you to cancel slow-running queries that would, otherwise, put pressure on database resources.

A beginner’s guide to JPA and Hibernate query hints

Introduction In this article, we are going to see what JPA query hints are, and get to know all the query hints supported by Hibernate. Understanding the Hibernate query hints is very important when developing a non-trivial enterprise application since they allow you to customize the way queries are executed by Hibernate.

The best way to map an entity version property with JPA and Hibernate

Introduction In this article, we are going to see what is the best way to map the entity version property with JPA and Hibernate. Most often, we overlook the basic entity type mappings, focusing more on associations or querying options. However, basic types can also have a significant impact on application performance, especially if the type in question is used in many entity mappings.

Optimistic locking version property with JPA and Hibernate

Introduction In this article, we are going to see how optimistic locking version property works when using JPA and Hibernate. Most often, we overlook basic concepts and focus only on more advanced topics such as associations or queries, without realizing that basic mappings can also have a significant impact when it comes to persistence effectiveness and efficiency.

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