What is an Index in an SQL Server Database?

Question

Ashutosh Patel · Answer

SQL Server Index

An index in a SQL database is a data structure that improves the speed of data retrieval in a database table at the expense of additional space and reduced performance in write operations

Example-
Suppose you have a table Employee with the columns emp_id, name, age, and department_id. If you frequently search for employees based on their emp_id, creating an index on the emp_id column can greatly speed up those search operas

This SQL statement creates an index named idemployee_id in the emp_id column of the Employee table.

CREATE INDEX idemployee_id ON Employees(emp_id);

The database engine can use the idemployee_id index to quickly find rows where emp_id is equal to 1001, rather than scanning the entire Employees table sequentially.

SELECT * FROM employees WHERE employee_id = 1001;

Also, Read: What are SQL Stored Procedures in the Database?

interview

What is an Index in an SQL Server Database?

Can you answer this question?

1 Answers

SQL Server Index