Index types in SQL Server

 

Index type	Description	Other information
Aggregation	Clustered indexes sort and store data rows in tables or views in sequence based on the clustered index key. Clustered indexes are implemented based on the B-tree index structure. The B-tree index structure supports fast row search based on the clustered index key value.	Clustered index design guide Clustered Index Structure
Non-aggregation	You can use clustered indexes to define non-clustered indexes for tables or views, or define non-clustered indexes based on the heap. Each index row in a non-clustered index contains a non-clustered key value and a row locator. This locator points to the data row containing the key value in the clustered index or heap. Rows in the index are stored in the order of the index key value, but data rows are not stored in any specific order unless a clustered index is created on the table.	Non-clustered index design guide Non-clustered Index Structure
Unique	The unique index ensures that the index key does not contain duplicate values. Therefore, each row in a table or view is unique to some extent. Both clustered and non-clustered indexes can be unique indexes.	Unique index design guide
Include column Index	A non-clustered index that extends to include not only key columns but also non-key columns.	Index with included Columns
Index View	The index of a view is embodied (executed), and the result set is permanently stored in a unique clustered index. The storage method is the same as that of a table with clustered indexes. After creating a clustered index, you can add a non-clustered index to the view.	Design Index View
Full text	A special type of tag-based functional index, which is generated and maintained by the Microsoft SQL Server full-text engine. It is used to search for complex words in string data.	Full-text index
Space	By using spatial indexes, you can more efficientlyGeometrySpatial objects (spatial data) in columns of the Data Type . Spatial indexes can reduce the number of objects that require a relatively large amount of space operations.	Spatial Index Overview
Filter	An Optimized non-clustered index is especially suitable for queries that cover the selection of data from a well-defined data subset. Filter indexes use filter predicates to index some rows in the table. Compared with full table indexes, well-designed screening indexes can improve query performance, reduce index maintenance overhead, and reduce index storage overhead.	Design Criteria for filtering Indexes
XML	XMLThe partitioned persistent representation of the XML Binary Large Object (BLOB) in the data type column.	Index of XML data type columns