Statistics and Cost Estimation - Inside the SQL Server Query Optimizer - page 89

Now run the following query:
SELECT * FROM dbo . SalesOrderDetail
WHERE SalesOrderID = 43670 AND OrderQty = 1
Listing 3-22.
Use the previous sys.stats query from Listing 3-21 to verify that two statistics
objects were created, one for the SalesOrderID column, and a second for the OrderQty
column. Now create the following index, and run the sys.stats query again to verify
that a new statistics object for the ProductID column has been created.
CREATE INDEX IX_ProductID ON dbo . SalesOrderDetail ( ProductID )
Listing 3-23.
This will be the output of the sys.stats query so far:
name auto_created update_date
-------------------------- ------------ -----------------------
_WA_Sys_00000004_76EBA2E9 1 2010-03-01 14:17:44.610
_WA_Sys_00000001_76EBA2E9 1 2010-03-01 14:17:44.770
IX_ProductID 0 2010-03-01 14:19:00.607
Listing 3-24.
Notice how the value of the auto_created column, which indicates if the statistics were
created by the Query Optimizer, is 0 for the IX_ProductID statistics object. Run the
next command to update just the column statistics:
UPDATE STATISTICS dbo . SalesOrderDetail WITH FULLSCAN , COLUMNS
Listing 3-25.