Hibernate is a light-weight open source ORM tool used for mapping between database tables and respective Java classes. It is an open source tool and can be downloaded free of cost. An ORM (Object Relational Mapping) tool is majorly used to store, modify and retrieve data from a database.
How does Hibernate function?
Hibernate will form a skin between the database and the applications and help configure mappings, connection strings and entity classes. This user-friendly ORM tool will create persistent data and will also help you in synchronizing them. You do not need to create database tables or generate database queries manually. The OMR tool will perform the functions for you. It is easy to install and helps in simplifying complex operations.
There are various other questions which you might have or people might ask you about Hibernate. Some of the frequently asked Hibernate interview questions are stated below.
a) What are the major interfaces included in Hibernate?
Well, the core Hibernate framework interface includes Configuration, Session, Session Factory, Criteria, Query and Transaction.
b) Now, these terms are not for laymen. So obviously, an evident question which can be asked to you will be to define Session Factory.
The Session Factory contains the second level cache data among the two available types. It provides a factory at the session’s instance and it is not enabled by default. You need to enable it manually.
c) Or, you can also be asked to define Session first.
Session maintains the connection between Hibernate applications and the database. It is used for storing, retrieving, updating or erasing data from the database.
d) Another probable question is, what is the job of a configuration interface?
A configuration interface sets up the Hibernate sessions. In other words, it bootstraps Hibernate.
e) The next common question asked is, what query language does hibernate use?
The Hibernate uses an extension of SQL known as HQL (Hibernate Query Language). It is simpler, flexible and efficient than SQL and can perform multiple operations on a database.
f) How does Hibernate perform so fast?
There is a feature in Hibernate called the Dirty Checking Feature. This feature will update only those fields which require a change. The other fields will be left intact and untouched. This will reduce the writing time and make the tool work faster.
g) How does hibernate facilitate Java functions?
The Java Database Connectivity or popularly known as JDBC provides a set of Java API to Hibernate. This helps Hibernate access multiple relational databases present in a Java program.
h) There are two levels of Cache which confuses many. What is a first level cache when it comes to Hibernate?
The first level cache is a session cache. It is mandatory for all the requests to pass through session cache. Before you add any object to the database, the session cache keeps that object primarily under its own control.
i) Define Second-level Cache.
The session cache is always consulted before an object is located in the second level cache. The second level cache is optional and not as important as the first one.
With all these features, Hibernate definitely works as a superpower to the field of Java Development.