---
title: "What are all the different types of indexes?"  
description: "What are all the different types of indexes?"  
author: "Manish Kumar"  
published: 2017-06-12  
updated: 2020-09-22  
canonical: https://www.mindstick.com/interview/23261/what-are-all-the-different-types-of-indexes  
category: "mssql server"  
tags: ["database", "sql server"]  
reading_time: 1 minute  

---

# What are all the different types of indexes?

**There are three types of indexes -.**

**Unique Index.**

Unique indexing does not allow the field to have duplicate values if the column is unique indexed. This index can be applied automatically when primary key is defined.

**Clustered Index.**

Clustered index reorders the physical order of the table and search based on the key values. Each table can have only one clustered index.

**NonClustered Index.**

This type of Index does not alter the physical order of the table and maintains logical order of data. In this Each table can have 999 nonclustered indexes.

## Answers

### Answer by Manish Kumar

**There are three types of indexes -.**

**Unique Index.**

Unique indexing does not allow the field to have duplicate values if the column is unique indexed. This index can be applied automatically when primary key is defined.

**Clustered Index.**

Clustered index reorders the physical order of the table and search based on the key values. Each table can have only one clustered index.

**NonClustered Index.**

This type of Index does not alter the physical order of the table and maintains logical order of data. In this Each table can have 999 nonclustered indexes.


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