A clustered index is a type of index that determines the physical order of data in a table.
Table data can be sorted in only way, therefore, there can be only one clustered index per table.
In SQL Server, if you set a primary key on a column, then it will automatically create a clustered index on that particular column.
A clustered index in SQL Server is a database index that determines the
physical order of data in a table. It reorganizes the data rows to match
the order of the clustered index key, leading to faster data retrieval
for queries involving the indexed columns. Unlike non-clustered indexes,
there can be only one clustered index per table. Clustered indexes
optimize range-based searches and improve overall query performance for
the indexed columns.
