Difference between Clustered Index and Non-Clustered Index

In this post, I will explain the difference between Clustered Index and Non-Clustered Index.

Indexes are used to quickly locate data without having to search every row in a database table. An index is a copy of selected columns of data from a table that can be searched very efficiently that also includes a low-level disk block address or direct link to the complete row of data it was copied from. 

 A table can have two types of indexes:

1. Clustered Index
2. Non-Clustered Index 

 Difference between Clustered Index and Non-Clustered Index

Sr No	Clustered Index	Non-Clustered Index
1	There can be only one Clustered Indexes for a table	There can be more than one Non-Clustered Indexes for a table
2	Data retrieval is faster than Non-Clustered Indexes	Data insertion/update is faster than Clustered Index
3	The leaf nodes of a Clustered Index contain the data pages	The leaf node of a Non-Clustered Index does not consist of the data pages. Instead, the leaf nodes contain index rows
4	Do not need extra space to store logical structure	Use extra space to store logical structure
5	Sort the records and store them physically according to the order	Do not affect the physical order. Create a logical order for data rows and use pointers to physical data files

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