Difference Between Clustered and Non-clustered index

In this post, we will understand the difference between clustered index and non-clustered index.

Clustered index

It is quick.
It requires less memory to perform operations.
The index is the main data.
A table can have one clustered index only.
It has inherent ability to store data on the disk.
It can store pointers to block not to data.
The leaf nodes contain actual data.
The clustered key defines the order of data within table.
It is a type of index where the table records are physically reordered to match with the index.

It is slower.
It requires more memory to perform operations.
The index is a copy of data.
A table can have multiple non-clustered indices.
It doesn’t have the inherent ability to store data on the disk.
It can store values as well as pointers to actual rows that contain data.
The leaf nodes are not actual data, they just contain included columns.
The index key is used to define the order of data within index.
It is a special type of index wherein the logical order of index doesn’t match with the physical stored order of the rows on the disk.

Published on 25-Mar-2021 05:48:22