Hibernate Best Practices – using sequences for bulk inserts

For many database tables, an auto increment column is used for the primary key. This is fine for inserting single values, but if you want to bulk insert hundreds or thousands of values and you need to refer to the new id columns for inserting other data, this is inefficient as Hibernate has to perform each one at a time to get the generated id. You can avoid this by using a database sequence to generate the ids. Then Hibernate can get a set of, say, 500 ids, and use them in newly created objects and other objects that link to them, and safely bulk insert them. Sample code:

@Entity
@Table(name = "my_entity")
public class MyEntity {
    @Id
    @GeneratedValue(generator = "my_entity_generator")
    @GenericGenerator(
            name = "my_entity_generator",
            strategy = "enhanced-sequence",
            parameters = {
                    @org.hibernate.annotations.Parameter(name="sequence_name", value = "my_entity_seq"),
                    @org.hibernate.annotations.Parameter(name="increment_size", value = "500"),
                    @org.hibernate.annotations.Parameter(name="optimizer", value = "pooled-lo")
            })
    private Long id;
}