What are all the different types of indexes?

There are three types of indexes -.

 

This indexing does not allow the field to have duplicate values if the column is unique indexed. Unique index can be applied automatically when primary key is defined.

 

This type of index reorders the physical order of the table and search based on the key values. Each table can have only one clustered index.

 

Non-Clustered Index does not alter the physical order of the table and maintains logical order of data. Each table can have 999 non-clustered indexes