You can create 999 Non Clustered Indexes per Table. How many Non Clustered Indexes in SQL Server? In this chapter, we will show you how to create and delete a non clustered index in SQL Server using Transact SQL Query, and SQL Server Management Studio Second, it will retrieve record (from the First table) at that row address

First, SQL will look for 79000 in the second table, and after finding the record, it will check the row address.

When you ask for customer records whose Income = 79000. It will store the Yearly income records in separate locations along with the row address. In this situation, you have to create a non clustered index on the Yearly Income column. Assume Customer key is Primary key (means Clustered Index), but you require to retrieve records by yearly Income. For example, if you had a Customer table with the following records. Let me show you what will happen if you create a Non clustered Index in SQL Server. Say, you want to retrieve employees by their sales (which is a regular report), then you can use a non clustered index on Sales to retrieve the records quickly. The non clustered index in SQL Server is useful to improve the query performance. SQL Server allows you to create almost 999 non clustered indexes per table.

A Non Clustered Index in SQL Server stores the index structure separately from the data physically stored in a table.

Sql server indexing