When we work with entity relationships in JPA (like @OneToMany, @OneToOne, @ManyToOne, etc.), two important features come into play to manage entity lifecycle propagation and child deletion: Although they may seem similar because both can trigger child deletions, their behavior and purpose are quite different. 1. What is CascadeType.ALL? CascadeType.ALL is a lifecycle propagation rule.It…

Entity listeners in JPA are used to react to lifecycle events of entities, such as creation, update, or deletion. They allow you to execute logic automatically whenever certain events occur, without polluting your service or repository layer with repetitive code. Here’s a detailed explanation with a scenario: 1. What Are Entity Listeners 2. Scenario: Audit…

In Spring Boot with JPA/Hibernate, you can automatically track entity creation and update timestamps by using JPA auditing. This allows you to maintain fields like createdAt and updatedAt without manually setting them in every service method. Here’s a detailed guide: 1. Enable JPA Auditing In your Spring Boot application, enable auditing by adding @EnableJpaAuditing to…

1. Overview In high-scale applications where a single database instance becomes a bottleneck, sharding and partitioning are two strategies used to improve performance, scalability, and manageability. While JPA (Java Persistence API) doesn’t natively support sharding or partitioning, it can be extended to implement these strategies using custom logic, multi-datasource configuration, and routing mechanisms. 2. Sharding…

1. Overview Hibernate’s dirty checking is a powerful feature that automatically detects which fields have changed in an entity and generates only the required SQL UPDATE statements. While this simplifies development, it can become a performance bottleneck, especially during batch operations (e.g., updating thousands of entities in a loop). 2. What is Dirty Checking in…

What is Pagination? Pagination is the process of dividing large data sets into smaller, manageable chunks, called pages. Instead of returning all rows from a database table (which can be thousands), you fetch a limited number of rows per request (like 10, 20, or 50). Why Use Pagination? Pagination Support in Spring Data JPA Spring…

1. What is SessionFactory? Hibernate is a powerful Object-Relational Mapping (ORM) framework for Java that simplifies database interactions. At its core, two crucial interfaces, SessionFactory and Session, are fundamental to its operation. Understanding their roles and differences is key to effectively using Hibernate. 1.1 Understanding SessionFactory The SessionFactory in Hibernate is a heavyweight, thread-safe object…

Differences Aspect get() load() Retrieval Strategy Eager loading (hits the database immediately) Lazy loading (returns a proxy and hits DB only when needed) When is the DB hit? Immediately when get() is called Only when you access a non-identifier property (lazy init) Return type Actual object or null Proxy object (subclass proxy) What if object…

Introduction The N+1 problem in Hibernate is a common performance issue that occurs when an application executes excessive database queries due to improper handling of relationships. This can severely degrade application performance, especially when dealing with large datasets. Understanding the N+1 Problem What is the N+1 Problem? The N+1 problem occurs when Hibernate retrieves a…

Introduction One-to-One mapping in Hibernate represents a relationship where each record in one table corresponds to exactly one record in another table. This is commonly used when entities have exclusive relationships, such as User and Address. In this tutorial, we will: Project Setup Ensure you have the following dependencies in your pom.xml: Database Configuration Configure…