How does Hibernate handle JPA Criteria API literals
Introduction The JPA specification is like a Java interface, However, when it comes to performance, implementation details matter a lot. That’s why, even if you use the JPA standard, you still need to know how the underlying provider implements the standard specification. For instance, if we take this tweet from Gareth Western: We can clearly see that there is an issue in the way literals might be handled by Hibernate when executing a Criteria API query. Therefore, in this article, we are going to see how literals are handled by Hibernate and… Read More
JPA and Hibernate FetchType EAGER is a code smell
Introduction Hibernate fetching strategies can really make a difference between an application that barely crawls and a highly responsive one. In this post, I’ll explain why you should prefer query-based fetching instead of global fetch plans. Fetching 101 Hibernate defines four association retrieving strategies: Fetching Strategy Description Join The association is OUTER JOINED in the original SELECT statement Select An additional SELECT statement is used to retrieve the associated entity(entities) Subselect An additional SELECT statement is used to retrieve the whole associated collection. This mode is meant for to-many associations Batch An… Read More
JPA Criteria API can generate unexpected SQL statements
Introduction In this article, we are going to learn why you should always check the SQL statements generated by JPA Criteria API queries when using Hibernate. Criteria API is very useful for dynamically building queries, but that’s the only use case where I’d use it. Whenever you have a UI with N filters that may arrive in any M combinations, it makes sense to have an API to construct queries dynamically since concatenating strings is always a path I’m running away from. The question is, are you aware of the SQL queries… Read More
