Confusion about an Indexed View - sql-server-2008

Question

I have the following indexed view:
ALTER View [CIC].[vwCoaterC473Heat] WITH SCHEMABINDING
AS
Select
id as ID,
DATEADD(ms, -DATEPART(ms, read_time), read_time) as ReadTime,
equipment_id as EquipmentID,
...
...
From dbo.td_coater_c473_heat
Where read_time >= Convert(dateTime,'1/1/2012',120)
CREATE UNIQUE CLUSTERED INDEX [IX_vwCoaterC473Heat_ReadTime_EquipmentID_ID]
ON [CIC].[vwCoaterC473Heat]
(
[ReadTime] ASC,
[EquipmentID] ASC,
[ID] ASC
)
GO
And I have the following query that references the indexed view:
Select
r.Coater,
r.ReadTime,
C473_left_A_actual_Temp,
C473_right_A_actual_Temp,
C473_left_B_actual_Temp,
C473_right_B_actual_Temp,
HD02A_Actual_Voltage,
HD02A_Actual_Current,
HD02B_Actual_Voltage,
HD02B_Actual_Current
From Cic.RandyTemp r
Inner Join Cic.vwCoaterC473Heat a
On a.EquipmentId = r.Coater And a.ReadTime = r.ReadTime
The query plan generated from this looks as follows:
I'm curious why SQL Server is bypassing the persisted data from the indexed view, and querying the underlying table the view is based on.

Answer 1

Are you using SQL Server Standard Edition? If so you need to use the WITH (NOEXPAND) hint. Please try this version and see if the indexed view is used. It might just be that the optimizer has decided that accessing the index in the base table is more efficient.
SELECT
r.Coater,
r.ReadTime,
C473_left_A_actual_Temp, -- why no alias prefixes from here down?
C473_right_A_actual_Temp,
C473_left_B_actual_Temp,
C473_right_B_actual_Temp,
HD02A_Actual_Voltage,
HD02A_Actual_Current,
HD02B_Actual_Voltage,
HD02B_Actual_Current
FROM Cic.RandyTemp AS r
INNER JOIN Cic.vwCoaterC473Heat AS a WITH (NOEXPAND)
ON a.EquipmentId = r.Coater
AND a.ReadTime = r.ReadTime;