Cannot create %S_MSG on view "%.*ls" because it contains the DISTINCT keyword. Consider removing DISTINCT from the view or not indexing the view. Alternatively, consider replacing DISTINCT with GROUP BY or COUNT_BIG(*) to simulate DISTINCT on groupin

Error Message:
Msg 10100, Level 16, State 1, Line 2
Cannot create %S_MSG on view "%.*ls" because it contains the DISTINCT keyword. Consider removing DISTINCT from the view or not indexing the view. Alternatively, consider replacing DISTINCT with GROUP BY or COUNT_BIG(*) to simulate DISTINCT on grouping columns.

Severity level:
16.

Description:
This error message appears when you try to use the DISTINCT keyword in an indexed view.

Consequences:
The T-SQL statement can be parsed, but causes the error at runtime.

Resolution:
Errors of the Severity Level 16 are generated by the user and are corrigible by the user. The statement cannot be executed this way. You must remove the DISTINCT keyword.

Versions:
All versions of SQL Server.

Example(s):
USE Northwind;
GO

SET NUMERIC_ROUNDABORT OFF;
SET ANSI_PADDING,
    ANSI_WARNINGS,
    CONCAT_NULL_YIELDS_NULL,
    ARITHABORT,
    QUOTED_IDENTIFIER,
    ANSI_NULLS ON;
GO

IF OBJECT_ID ('dbo.MyOrderView', 'View') > 0
   DROP VIEW dbo.MyOrderView;
GO
CREATE VIEW dbo.MyOrderView
WITH SCHEMABINDING
AS
SELECT DISTINCT SUM(UnitPrice*Quantity*(1.00-Discount)) AS Revenue,
    OrderDate, ProductID, COUNT_BIG(*) AS MyCount
  FROM dbo.[Order Details] AS od
  JOIN dbo.Orders AS o
    ON od.OrderID = o.OrderID
 GROUP BY OrderDate, ProductID;
GO

CREATE UNIQUE CLUSTERED INDEX cix_MyOrderView
    ON dbo.MyOrderView (OrderDate, ProductID);
GO

Remarks:
In the above example we try to use the DISTINCT keyword in an indexed view. This raises the error.