Hands-On High Performance with Spring 5

Constructor-based HQLs

In typical situations, when an application is utilizing Hibernate, we don't try to recover the entire substance with every one of its properties despite the fact that we need not bother with every one of them for a specific use case. A solitary substance may have 30 properties, while we may only need a couple to be set in our feature or shown to the client. In such a case, a huge number of records are retrieved with the query to the database. It adds up to a significant load considering the unused fields sticking with the application, which will eventually be a gigantic execution or performance hit.

To manage this, HQL/JPA gives us a select new constructor call, which is frequently utilized for detailing inquiries, ...