Poor performance querying view from sproc

We are using SQL SERVER 2005.

We have been experiencing horrible performance running select queries from sprocs against views that do outer joins, despite having optimized all of the indexes.

Our solution in these cases (and arguably not the best) has been to first select the views into a temp table and then query the temp table for the desired result set. This has greatly improved the speed of which our sprocs run, but we are looking for a better solution.

Has anybody else experienced this problem?

Thanks in advance.

Hi Eric. Would it be possible for you to post some sample code that includes some of the view definitions, table structures, and sample data scripts? It's quite tough to try and guess what the issue may be.

One thing that comes to mind would be if you selecting only a subset of the columns from the view into a temp table and then joining/selecting from that multiple times, you could be bypassing many bookmark/cluster key lookups, but that is a total shot in the dark. If you can post some scripts, that would help us try and help you. You can get the DDL for the tables/indexes/views by simply scripting the appropriate tables from SSMS/QA...

HTH,

Chad

|||

Are you joining multiple views? Or just a view that joins multiple tables?

What I would do is use a trial replacement for your current implimentation where you create the join etc (as you have in the view) in the query where you actually use the view.

I am not 100% sure how views work in MSSQL, but I hope this can be of some assistance.

|||Can you please paste your stored procedure code. I suspect it is due to the selectivity of the predicates that means you are getting a poor plan. If you can past the output of show plan that would also help.|||We have experienced exactly the same thing. Queries which work fine in 1-5 seconds on SQL 2000 SP4 either run very long or never finish in hours under SQL 2005. I have posted several posts here and never gotten any responses.

We are running SQL 2005 9.0.2153 on SQL 2003 SP1 64bit. The problem seems to be related to views with RIGHT outer joins.

Here is my duplication script, which fails on 2 different SQL 2005 installations.

-- Create Test Data Table CustomerListTom and Views

USE AdventureWorks
GO

IF EXISTS (SELECT * FROM sys.views WHERE object_id = OBJECT_ID(N'ViewATom'))
DROP VIEW [ViewATom]

IF EXISTS (SELECT * FROM sys.views WHERE object_id = OBJECT_ID(N'ViewBTom'))
DROP VIEW [ViewBTom]

IF EXISTS (SELECT * FROM sys.objects WHERE object_id = OBJECT_ID(N'CustomerListTom') AND type in (N'U'))
DROP TABLE CustomerListTom
GO

CREATE TABLE [dbo].[CustomerListTom](
[CustomerID] [varchar](6) COLLATE SQL_Latin1_General_CP1_CI_AS NOT NULL,
[RegionID] [varchar](3) COLLATE SQL_Latin1_General_CP1_CI_AS NOT NULL,
[FirstName] [dbo].[Name] NOT NULL,
[LastName] [dbo].[Name] NOT NULL,
[EmailAddress] [nvarchar](50) COLLATE SQL_Latin1_General_CP1_CI_AS NULL,
[AddressLine] [nvarchar](60) COLLATE SQL_Latin1_General_CP1_CI_AS NOT NULL,
[AddressCity] [nvarchar](30) COLLATE SQL_Latin1_General_CP1_CI_AS NOT NULL,
[AddressState] [nchar](3) COLLATE SQL_Latin1_General_CP1_CI_AS NOT NULL,
[AddressZip] [nvarchar](15) COLLATE SQL_Latin1_General_CP1_CI_AS NOT NULL,
[AddressCountry] [dbo].[Name] NOT NULL,
[Phone] [dbo].[Phone] NULL,
[BillAddressLine] [nvarchar](60) COLLATE SQL_Latin1_General_CP1_CI_AS NOT NULL,
[BillAddressCity] [nvarchar](30) COLLATE SQL_Latin1_General_CP1_CI_AS NOT NULL,
[BillAddressState] [nchar](3) COLLATE SQL_Latin1_General_CP1_CI_AS NOT NULL,
[BillAddressZip] [nvarchar](15) COLLATE SQL_Latin1_General_CP1_CI_AS NOT NULL,
[BillAddressCountry] [dbo].[Name] NOT NULL,
[BillPhone] [dbo].[Phone] NULL,
[ModifiedDate] [datetime] NOT NULL,
)

INSERT INTO CustomerListTom
SELECT
CustomerID = RIGHT(cu.AccountNumber,6),
RegionID = RIGHT('000'+CAST(cu.TerritoryID AS VARCHAR(3)),3),
FirstName = ct.FirstName,
LastName = ct.LastName,
EmailAddress = ct.EmailAddress,
AddressLine = ad.AddressLine1,
AddressCity = ad.City,
AddressState = sp.StateProvinceCode,
AddressZip = ad.PostalCode,
AddressCountry = sp.[Name],
Phone = ct.Phone,

BillAddressLine = ad.AddressLine1,
BillAddressCity = ad.City,
BillAddressState = sp.StateProvinceCode,
BillAddressZip = ad.PostalCode,
BillAddressCountry = sp.[Name],
BillPhone = ct.Phone,

ModifiedDate = cu.ModifiedDate
--,*
FROM Sales.Customer cu
JOIN Sales.Individual id ON id.CustomerID = cu.CustomerID
JOIN Person.Contact ct ON ct.ContactID = id.ContactID
JOIN Sales.CustomerAddress ca ON cu.CustomerID = ca.CustomerID
JOIN Person.Address ad ON ad.AddressID = ca.AddressID
JOIN Person.StateProvince sp ON sp.StateProvinceID = ad.StateProvinceID

-- Create a big enough set of data for testing
DECLARE @.i INT
SET @.i = 1
WHILE (@.i < 30)
BEGIN
INSERT INTO CustomerListTom
SELECT TOP 15 PERCENT
CustomerID = RIGHT(cu.AccountNumber,6),
RegionID = RIGHT('000'+CAST(cu.TerritoryID+@.i AS VARCHAR(3)),3),
FirstName = ct.FirstName,
LastName = ct.LastName,
EmailAddress = ct.EmailAddress,
AddressLine = ad.AddressLine1,
AddressCity = ad.City,
AddressState = sp.StateProvinceCode,
AddressZip = ad.PostalCode,
AddressCountry = sp.[Name],
Phone = ct.Phone,
BillAddressLine = ad.AddressLine1,
BillAddressCity = ad.City,
BillAddressState = sp.StateProvinceCode,
BillAddressZip = ad.PostalCode,
BillAddressCountry = sp.[Name],
BillPhone = ct.Phone,

ModifiedDate = cu.ModifiedDate + CASE WHEN @.i > 3 THEN 10 ELSE -25 END + @.i

FROM Sales.Customer cu
JOIN Sales.Individual id ON id.CustomerID = cu.CustomerID
JOIN Person.Contact ct ON ct.ContactID = id.ContactID
JOIN Sales.CustomerAddress ca ON cu.CustomerID = ca.CustomerID
JOIN Person.Address ad ON ad.AddressID = ca.AddressID
JOIN Person.StateProvince sp ON sp.StateProvinceID = ad.StateProvinceID

SET @.i = @.i + 1
END

-- Cleanup - Delete Dups for PK
DELETE FROM CustomerListTom
WHERE CustomerID+RegionID IN (
SELECT CustomerID+RegionID
FROM CustomerListTom cu
GROUP BY CustomerID, RegionID
HAVING COUNT(*) > 1)

ALTER TABLE [CustomerListTom]
ADD CONSTRAINT [PK_CustomerListTom] PRIMARY KEY CLUSTERED
(
[CustomerID] ASC,
[RegionID] ASC
)

GO

-- Create Views
GO
CREATE VIEW ViewATom
AS
SELECT *
FROM CustomerListTom cu
WHERE cu.RegionID = '004'
UNION
SELECT *
FROM CustomerListTom cu
WHERE CustomerID NOT IN
(SELECT CustomerID FROM CustomerListTom c2 WHERE c2.RegionID = '004')
AND (CustomerID + CONVERT(char(8), ModifiedDate, 112) + RegionID IN
(SELECT MAX(CustomerID + CONVERT(char(8), ModifiedDate, 112) + RegionID)
FROM CustomerListTom
GROUP BY CustomerID))

GO
CREATE VIEW ViewBTom
AS
SELECT DISTINCT CustomerID
FROM CustomerListTom
GO
--return

USE AdventureWorks

-- FAILURE
-- This query FAILS to return in over 15 mins, cancelled
SELECT TABLEB.CustomerID,
TABLEC.RegionID,
TABLEC.LastName,
TABLEC.FirstName
FROM ViewATom TABLEA
RIGHT OUTER JOIN ViewBTom TABLEB ON TABLEA.CustomerID = TABLEB.CustomerID
RIGHT OUTER JOIN CustomerListTom TABLEC ON TABLEC.CustomerID = TABLEB.CustomerID
WHERE TABLEB.CustomerID IN
('012870','012997','011000','011001','011002','011003','011004','011005','011006','011007',
'011008','011009','011010','011011','011012','011013','011014','011015','011016','011017',
'011018','011019','011020','011150','011153','011144','017230','017220','017254','017257',
'025338','025333','025338','025397','025389','025424','025483','025485','025682','025673',
'029478','029405','029402','029317','029109','018393'
)

return

-- SOLUTIONS
-- Change WHERE TABLEB to WHERE TABLEA, this query returns in less than 1 second
SELECT TABLEB.CustomerID,
TABLEC.RegionID,
TABLEC.LastName,
TABLEC.FirstName
FROM ViewATom TABLEA
RIGHT OUTER JOIN ViewBTom TABLEB ON TABLEA.CustomerID = TABLEB.CustomerID
RIGHT OUTER JOIN CustomerListTom TABLEC ON TABLEC.CustomerID = TABLEB.CustomerID
WHERE TABLEA.CustomerID IN
('012870','012997','011000','011001','011002','011003','011004','011005','011006','011007',
'011008','011009','011010','011011','011012','011013','011014','011015','011016','011017',
'011018','011019','011020','011150','011153','011144','017230','017220','017254','017257',
'025338','025333','025338','025397','025389','025424','025483','025485','025682','025673',
'029478','029405','029402','029317','029109','018393'
)

return

-- Remove RIGHT OUTER on TABLEB, this Query returns in less than 2 seconds
SELECT TABLEB.CustomerID,
TABLEC.RegionID,
TABLEC.LastName,
TABLEC.FirstName
FROM ViewATom TABLEA
JOIN ViewBTom TABLEB ON TABLEA.CustomerID = TABLEB.CustomerID
RIGHT OUTER JOIN CustomerListTom TABLEC ON TABLEC.CustomerID = TABLEB.CustomerID
WHERE TABLEB.CustomerID IN
('012870','012997','011000','011001','011002','011003','011004','011005','011006','011007',
'011008','011009','011010','011011','011012','011013','011014','011015','011016','011017',
'011018','011019','011020','011150','011153','011144','017230','017220','017254','017257',
'025338','025333','025338','025397','025389','025424','025483','025485','025682','025673',
'029478','029405','029402','029317','029109','018393'
)

return

-- Drop PK and run ORIGINAL query, returns in less than 4 seconds

IF EXISTS (SELECT * FROM sys.indexes WHERE object_id = OBJECT_ID(N'[dbo].[CustomerListTom]') AND name = N'PK_CustomerListTom')
ALTER TABLE [dbo].[CustomerListTom] DROP CONSTRAINT [PK_CustomerListTom]
GO

SELECT TABLEB.CustomerID,
TABLEC.RegionID,
TABLEC.LastName,
TABLEC.FirstName
FROM ViewATom TABLEA
RIGHT OUTER JOIN ViewBTom TABLEB ON TABLEA.CustomerID = TABLEB.CustomerID
RIGHT OUTER JOIN CustomerListTom TABLEC ON TABLEC.CustomerID = TABLEB.CustomerID
WHERE TABLEB.CustomerID IN
('012870','012997','011000','011001','011002','011003','011004','011005','011006','011007',
'011008','011009','011010','011011','011012','011013','011014','011015','011016','011017',
'011018','011019','011020','011150','011153','011144','017230','017220','017254','017257',
'025338','025333','025338','025397','025389','025424','025483','025485','025682','025673',
'029478','029405','029402','029317','029109','018393'
)

return

-- Create PK with NONCLUSTERED and run ORIGINAL query, returns in less than 1 second

IF EXISTS (SELECT * FROM sys.indexes WHERE object_id = OBJECT_ID(N'[dbo].[CustomerListTom]') AND name = N'PK_CustomerListTom')
ALTER TABLE [dbo].[CustomerListTom] DROP CONSTRAINT [PK_CustomerListTom]
GO
ALTER TABLE [CustomerListTom]
ADD CONSTRAINT [PK_CustomerListTom] PRIMARY KEY NONCLUSTERED
(
[CustomerID] ASC,
[RegionID] ASC
)
GO

SELECT TABLEB.CustomerID,
TABLEC.RegionID,
TABLEC.LastName,
TABLEC.FirstName
FROM ViewATom TABLEA
RIGHT OUTER JOIN ViewBTom TABLEB ON TABLEA.CustomerID = TABLEB.CustomerID
RIGHT OUTER JOIN CustomerListTom TABLEC ON TABLEC.CustomerID = TABLEB.CustomerID
WHERE TABLEB.CustomerID IN
('012870','012997','011000','011001','011002','011003','011004','011005','011006','011007',
'011008','011009','011010','011011','011012','011013','011014','011015','011016','011017',
'011018','011019','011020','011150','011153','011144','017230','017220','017254','017257',
'025338','025333','025338','025397','025389','025424','025483','025485','025682','025673',
'029478','029405','029402','029317','029109','018393'
)

return