Cannot create %S_MSG on view "%.*ls" because it uses aggregate "%.*ls". Consider eliminating the aggregate, not indexing the view, or using alternate aggregates. For example, for AVG substitute SUM and COUNT_BIG, or for COUNT, substitute COUNT_BIG.

Error Message:
Msg 10125, Level 16, State 1, Line 2
Cannot create %S_MSG on view "%.*ls" because it uses aggregate "%.*ls". Consider eliminating the aggregate, not indexing the view, or using alternate aggregates. For example, for AVG substitute SUM and COUNT_BIG, or for COUNT, substitute COUNT_BIG.

Severity level:
16.

Description:
This error message appears when you try to use certain aggregate functions 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 this aggregate function and rewrite the statement in order to achieve the same result.

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 AVG(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 AVG aggregate function in an indexed view. This raises the error.