We can refer to a clustered table as one that has a clustered index. Since the data rows are stored in one direction, each table can only have a single clustered index.Ī table stored the rows in sorted order only when the table has a clustered index. It always stores the index value in a B-tree structure where the actual data is stored in the leaf node. They are included in the index definition. There are mainly two types of indexes in SQL Server: ClusteredĬlustered indexes use key values for sorting and storing data rows in tables or view. They are stored in a structure (B-tree) that helps SQL Server users quickly and efficiently find the rows or rows associated with the key values. This article will give you an overview of SQL Server indexes, including how they're described inside a database and how they can speed up querying.Īn index is a set of keys made up of single or multiple columns in a table or view. We can have the CREATE INDEX, DROP INDEX, and ALTER INDEX SQL commands for creating new indexes, updating existing indexes, and deleting indexes in SQL Server. If we do not have an index, then it is very tough to locate the specific data. It makes the querying process fast by providing easy access to rows in data tables, similar to how a book's index will quickly locate information inside that book.

An index is one of the important paths to make the performance of SQL Server database high.

Sql server indexing