Hitachi Interview Questions and Answers for Freshers

Ansible playbook creation and execution

• Ansible is a tool used for automation and configuration management

• Playbooks are written in YAML format and define tasks to be executed

• Execution of playbooks can be done using the 'ansible-playbook' command

• Playbooks can be used for various tasks such as server provisioning, application deployment, etc.

Inner join returns only the rows that have matching values in both tables, while outer join returns all rows from both tables.

• Inner join: returns rows with matching values in both tables

• Outer join: returns all rows from both tables, with NULL values where there is no match

• Example: Inner join - SELECT * FROM table1 INNER JOIN table2 ON table1.id = table2.id

• Example: Outer join - SELECT * FROM table1 LEFT OUTER JOIN table2 ON table1.id = table2.id

Polymorphism is the ability of a single function or method to operate on different types of data.

• Polymorphism allows objects of different classes to be treated as objects of a common superclass.

• It enables a single interface to be used for different data types.

• Examples include method overloading and method overriding in object-oriented programming.

Multi threading is the ability of a CPU to execute multiple threads concurrently.

• Allows for parallel execution of tasks, improving performance

• Each thread has its own stack and runs independently

• Threads can communicate and synchronize using shared memory

• Examples: running multiple tasks simultaneously in a web server, processing data in parallel

A braking system is a mechanism that slows or stops the motion of a vehicle or machine.

• Braking systems convert kinetic energy into heat energy to slow or stop a vehicle or machine.

• There are several types of braking systems, including disc brakes, drum brakes, and regenerative brakes.

• Disc brakes use calipers to squeeze brake pads against a rotor, while drum brakes use shoes that press against a rotating drum.

• Regenerative brakes use the vehicle's momentum to generate electricit...read more