Performance antipatterns of one to many association in hibernate

Hibernate is the most popular ORM framework for Java. It is a straightforward and easy-to-use implementation of Java Persistence API. However, its simplicity of usage often becomes mischievous to developers and leads to serious performance issues in Hibernate-based applications. This paper presents five performance antipatterns related to the usage of one-to-many associations in Hibernate. These antipatterns focus on the problems of the owning side of collections, the Java types and annotations used in mappings, as well as processing of collections. Each antipattern consists of the description of a problem along with a sample code, negative performance consequences, and the recommended solution. Performance is analyzed in terms of the number and complexity of issued database statement. The code samples illustrate how the antipatterns decrease performance and how to implement the mappings to speed up the execution times.