non-clustered index

There can be more than one non-clustered index on a database table.

The section below contains statistics for the non-clustered indexes on the table.

However, the table may have non-clustered indices to allow fast retrieval of rows.

Create clustered and non-clustered indexes with unique or composite characteristics.

Clustered and non-clustered indexes are represented using B+ trees.

This ratio helps in estimating the cost of using a non-clustered index, or a clustered index on a DOL table.

Consequently a table scan (using a large I/O strategy, if the cache was configured with a large I/O pool) was often chosen over an available non-clustered index.

In Microsoft SQL Server, the leaf node of the clustered index corresponds to the actual data, not simply a pointer to data that resides elsewhere, as is the case with a non-clustered index.

The non-clustered index tree contains the index keys in sorted order, with the leaf level of the index containing the pointer to the record (page and the row number in the data page in page-organized engines; row offset in file-organized engines).