When is non clustered index used

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Featured on Meta. Now live: A fully responsive profile. Linked Related Skip to content. Clustered index stores data pages in the leaf nodes of the index while Non-clustered index method never stores data pages in the leaf nodes of the index. Cluster index offers faster data accessing, on the other hand, Non-clustered index is slower. Report a Bug. Previous Prev. Next Continue. Home Testing Expand child menu Expand. Put that clustered index on the datetime2 column!

All of the data for our row exists right beside our indexed columns. This is not necessarily true of other index types see nonclustered indexes below. Oh boy…. If a clustered index is like a phone book, a nonclustered index is like the index in the back of a chemistry text book.

So what do we do? Once we know the page number for noble gases from our index, we can flip to the correct page and get the data we need. This book index represents our nonclustered index. A nonclustered index contains the ordered data for the columns specified in that index, with pointers book page numbers that tell us where to go to find the rest of the data from that row flip to the right book page.

We can have as many nonclustered indexes on our tables as we want well, we max out at The output should be sorted in gender ascending and first name descending order. It means that the sequence of data will not be change and data will be returning on the same sequence in which its inserted.

Like Book, Non-Cluster index will be store in one place and data will be store in another place. This will allow creating more than one Non-cluster index on the table. How to create a Non-Cluster index? Differences between Cluster and Non-Cluster Index? Can have more than one Non-Cluster Index per table. Cannot consume extra disk storage as that only sort data row in the table Can consume more disk storage space as data and index will be store in different places.

It is faster than Non-Cluster Index. It is slower than Cluster index as it needs extra look up to search record. That's all for this article. I hope you enjoyed this article and find it useful. View All. Clustered Vs Non-Clustered Index.