Error 1902

Severity Level 16

Message Text

Cannot create more than one clustered index on table '%.*ls'. Drop the existing clustered index '%.*ls' before creating another.

Explanation

This error occurs when a table can have only one clustered index, but it can have many nonclustered indexes. Microsoft® SQL Server™ uses the clustered index to sort rows so that their physical order is the same as their logical (indexed) order. The bottom (leaf level) of a clustered index contains the actual data pages of the table.

In a nonclustered index, the physical order of the rows is not the same as the indexed order. In a nonclustered index, the bottom (leaf level) contains pointers to rows on data pages, which creates an extra level between the index structure and the data itself.

Action

Use the sp_helpindex system stored procedure to examine the existing indexes on the table. If a clustered index already exists, you must drop it before creating another clustered index.

See Also