Clustered Index in Sql Server |Clustered Index in DMBS With Example | Composite Clustered Index
What is SQL Server Clustered index?
The Clustered Index in SQL Server defines the order in which the data is physically stored in a table. That is the leaf node (Ref to the B-Tree Structure diagram) store the actual data. As the leaf nodes store the actual data, a table can have only one clustered index. The Clustered Index by default was created when we created the primary key constraint for that table. That means the primary key column creates a clustered index by default.
When a table has a clustered index then the table is called a clustered table. If a table has no clustered index, its data rows are stored in an unordered structure
Can we create multiple clustered indexes in a table in SQL Server?
It is not possible to create more than one clustered index in a table in SQL Server. The Employee table that we have just created already has one clustered Index on the Id column which already determines the physical storage order of the data in the table. Let us try to create another clustered Index on the Salary column and see what happens. Let us try to execute the following SQL Query.