 Hello, welcome to SSUnitech, so still decide and this is part 6 of SQL Server Performance Training. So today we gonna discuss about Non-Cluster Index. In our last video we have discussed about the cluster index and what are the indexes. So if you haven't watched last video of this video series. So I would strongly recommend watch that video before going forward. So let's start with Non-Cluster Index. So what is Non-Cluster Index? So it's an index like in textbook. The data is stored in one place and index are in other place. Like in textbook we have in the starting and end of the book we have the indexes. This is same like that. The index will have pointer to the storage location of the data. So table can have more than one Non-Cluster Index. But as we have discussed table can have only one cluster index. So this is a syntax for creating any Non-Cluster Index. So as we can see create Non-Cluster then the index, then index name on, then table name and then column names. So here we have only one column but in real time you may have more than one columns. So go to on SQL Server Management Studio to create the index on a table. As I am using SQL 2017 you may have another version of SQL Server but query would be same for all the versions. So this is the table which we have created in last video. So this is employee temperature table and here we will have only one cluster index which have been created in last video. So we can check. So this is our cluster index and here in the description we can check cluster and column is Add SID. So if we will have our query like this, select a stick from our table where in our condition we have city and this query is going to use again and again. So then we need to create one more index that would be Non-Cluster Index and column would be city. This is the query to create the Non-Cluster Index. Create Non-Cluster Index then the index name on, table name then city column. So let me execute this query. So command completed successfully that's why table will have one Non-Cluster Index. We can check and we can scroll down and here we will have Non-Cluster Index and in our description we can check Non-Cluster and column would be city. So this is Non-Cluster Index. So in our upcoming video once we will discuss about the scans and logical leads then we will check about the performance. How indexes will help to increase the performance. Next would be what are the differences between cluster index and Non-Cluster Index. So as I have told you only one cluster index can be per table and Non-Cluster Index more than one and maximum size would be triple nine and in cluster index it doesn't require any additional space. So in case of Non-Cluster Index it requires additional space. In case of cluster index demo queries would be faster but in case of Non-Cluster Index demo queries would be slow because it will need to update the index as well as the table. So this is the differences between Non-Cluster Index and cluster index. So thank you so much for watching this video. If you like this video please subscribe our channel to get many more videos. Don't forget to press the bell icon to get the notification of our upcoming videos. Thank you so much.