Explain the Stream API introduced in Java 8. How does it work?

The Stream API, introduced in Java 8, is a powerful feature that allows for functional-style operations on collections of data.

What are lambda expressions in Java? How do they simplify code?

Lambda expressions in Java are a feature introduced in Java 8 that provides a clear and concise way to represent instances of single-method interfaces

Explain the concept of OOP (Object-Oriented Programming) in Java.

Object-Oriented Programming (OOP) is a programming paradigm that revolves around the concept of objects, which are instances of classes

Explain the difference between TreeSet and HashSet in Java.

TreeSet and HashSet are two popular implementations of the Set interface in Java, each with distinct characteristics and use cases.

HashMap in Java and how does it work internally?

HashMap is a class that implements the Map interface, storing key-value pairs. It allows one null key and multiple null values.

Compare ArrayList and LinkedList in Java.

ArrayList and LinkedList are two commonly used implementations of the List interface in Java, each with distinct characteristics and use cases.

Explain the Aggregate functions in the SQL server.

Aggregate functions in SQL Server perform a calculation on a set of values and return a single value.

How do I handle NULL values in SQL Server queries and avoid common pitfalls?

Handling NULL values in SQL Server requires careful attention because NULL represents an unknown or missing value

MERGE statement in SQL Server to perform upserts (update/inserts).

The MERGE statement in SQL Server is a powerful way to perform "upserts" (a combination of inserts and updates).

How can I optimize SQL Server queries to improve performance?

Optimizing SQL Server queries to improve performance involves several strategies and techniques. Here are some key approaches: