Jun 25, 2007
I have a webpage that displays 4000 or more records in a GridView control powered by a SqlDataSource. It's very slow. I'm reading the following article on custom paging: http://aspnet.4guysfromrolla.com/articles/031506-1.aspx. This article uses an ObjectDataSource, and some functionality new to Sql Server 2005 to implement custom paging.There is a stored procedure called GetEmployeesSubestByDepartmentIDSorted that looks like this:ALTER PROCEDURE dbo.GetEmployeesSubsetByDepartmentIDSorted( @DepartmentID int, @sortExpression nvarchar(50), @startRowIndex int, @maximumRows int)AS IF @DepartmentID IS NULL -- If @DepartmentID is null, then we want to get all employees EXEC dbo.GetEmployeesSubsetSorted @sortExpression, @startRowIndex, @maximumRows ELSE BEGIN -- Otherwise we want to get just those employees in the specified department IF LEN(@sortExpression) = 0 SET @sortExpression = 'EmployeeID' -- Since @startRowIndex is zero-based in the data Web control, but one-based w/ROW_NUMBER(), increment SET @startRowIndex = @startRowIndex + 1 -- Issue query DECLARE @sql nvarchar(4000) SET @sql = 'SELECT EmployeeID, LastName, FirstName, DepartmentID, Salary, HireDate, DepartmentName FROM (SELECT EmployeeID, LastName, FirstName, e.DepartmentID, Salary, HireDate, d.Name as DepartmentName, ROW_NUMBER() OVER(ORDER BY ' + @sortExpression + ') as RowNum FROM Employees e INNER JOIN Departments d ON e.DepartmentID = d.DepartmentID WHERE e.DepartmentID = ' + CONVERT(nvarchar(10), @DepartmentID) + ' ) as EmpInfo WHERE RowNum BETWEEN ' + CONVERT(nvarchar(10), @startRowIndex) + ' AND (' + CONVERT(nvarchar(10), @startRowIndex) + ' + ' + CONVERT(nvarchar(10), @maximumRows) + ') - 1' -- Execute the SQL query EXEC sp_executesql @sql ENDThe part that's bold is the part I don't understand. Can someone shed some light on this for me? What is this doing and why?Diane
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Apr 22, 2008
I got problem with using custom paging in sql 2005
SET ANSI_NULLS OFF
GO
SET QUOTED_IDENTIFIER OFF
GO
ALTER PROCEDURE [dbo].[searchperson_view_general]
@Search nvarchar(2000)
,@OrderBy nvarchar (2000)
,@PageSize int
,@PageIndex int
AS
DECLARE @PageLowerBound int
DECLARE @PageUpperBound int
SET @PageLowerBound = @PageSize * @PageIndex
SET @PageUpperBound = @PageSize - 1 + @PageLowerBound
--Default order by to first column
IF (@OrderBy is null or LEN(@OrderBy) < 1)
BEGIN
SET @OrderBy = 'p.[person_id]'
END
-- SQL Server 2005 Paging
declare @SQL as nvarchar(4000)
SET @SQL = 'WITH PageIndex AS ('
SET @SQL = @SQL + ' SELECT distinct'
IF @PageSize > 0
BEGIN
SET @SQL = @SQL + ' TOP ' + convert(nvarchar, @PageUpperBound)
END
SET @SQL = @SQL + ' ROW_NUMBER() OVER (ORDER BY ' + @OrderBy + ') as RowIndex '
SET @SQL = @SQL + ', p.[person_id]'
SET @SQL = @SQL + ', p.[userType_id]'
SET @SQL = @SQL + ', p.[fullName]'
SET @SQL = @SQL + ', p.[gender_nm]'
SET @SQL = @SQL + ', p.[dateOfBirth] '
SET @SQL = @SQL + ', p.[positionTitle]'
SET @SQL = @SQL + ' FROM dbo.[person_view] p '
IF LEN(@Search) > 0
BEGIN
SET @SQL = @SQL + @Search
END
SET @SQL = @SQL + ' ) SELECT distinct'
SET @SQL = @SQL + ' p.person_id'
SET @SQL = @SQL + ', p.userType_id'
SET @SQL = @SQL + ', p.fullName'
SET @SQL = @SQL + ', p.gender_nm'
SET @SQL = @SQL + ', (year(getdate()) - year(p.[dateOfBirth])) as [dateOfBirth] '
SET @SQL = @SQL + ', p.positionTitle'
SET @SQL = @SQL + ' FROM PageIndex p '
SET @SQL = @SQL + ' WHERE RowIndex > ' + convert(nvarchar, @PageLowerBound)
IF @PageSize > 0
BEGIN
SET @SQL = @SQL + ' AND RowIndex <= ' + convert(nvarchar, @PageUpperBound)
END
SET @SQL = @SQL + ' ORDER BY ' + @OrderBy
exec sp_executesql @SQL
I checked my store procedure with parameters
exec [hr2b_searchperson_view_general_load]
'LEFT OUTER JOIN qualification
ON p.person_id = qualification.person_id
WHERE qualification.institutionName like N''%ABC%'''
,' p.person_id asc ', 25 , 1
This is a actual query show :
WITH PageIndex AS
( SELECT distinct TOP 49 ROW_NUMBER() OVER
(ORDER BY p.person_id asc )
as RowIndex
, p.[person_id]
, p.[userType_id]
, p.[fullName]
, p.[gender_nm]
, p.[dateOfBirth]
, p.[positionTitle]
FROM person_view p
LEFT OUTER JOIN qualification
ON p.person_id = qualification.person_id
WHERE qualification.institutionName like N'%ABC%' )
SELECT distinct
p.person_id
, p.userType_id
, p.fullName
, p.gender_nm
, (year(getdate()) - year(p.[dateOfBirth])) as [dateOfBirth]
, p.positionTitle
FROM PageIndex p
WHERE RowIndex > 25 AND RowIndex <= 49 ORDER BY p.person_id asc
If I used this query without using DISTINCT it will return extactly number of records which I expected but It is duplicated.
Then I tried to use DISTINCT in this query number of records return is less than 25 records . Because it was duplicated records when I used LEFT OUTER JOIN.But my query will be able to use more LEFT OUTER JOIN than this query. Please help me get exactly 25 records?
This is my tables
person_view(person_id, fullname, userType_id, gender_nm, dateOfBirth, positionTitle)
Qualification(qualification_id, qualification_nm,institutionName, person_id)
Thanks in advance.
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May 15, 2008
I was hoping I wouldn't be another poster with performance issues after migrating to SQl 2005 from SQL 2000 but here I am.
I am in the process of testing out our databases on Sql Server 2005 for migration from SQL Server 2000 and there are certain portions of code that have been affected negatively. I have read thru many of the posts here and have tried out most of the recommendations. I will start out with things I've done and then provide the actual SQL.
1) I have rebuilt all indexes ( using the DBCC REINDEX using the table option).
2) Updated the db engine to latest hot fix (build 3239) that addresses speed related fixes.
3) I also ran sp_createstats using the 'fullscan' option to create stats on all columns of all tables (minus indexed columns)
4) Since nothing seemed to work, I even ran UPDATE STATICS with FULL SCAN on all tables even though I did not need it as the REBUILD woudl have created stats. But I was willing to try anything.
I have confirmed that the execution plans are different even though the data on both sql 2000 and sql 2005 are identical (i put a copy on 2005). The plans themselves are huge as the queries are huge. Here is the query.
SELECT InterimView.* ,TestView.*
FROM View_LabDataExport_TestFormData_55 TestView
RIGHT OUTER JOIN ( SELECT ReqView.*, CDView.*
FROM View_LabDataExport_FormData_55 ReqView
LEFT OUTER JOIN View_LabDataExport_FormData_CD_55 CDView
ON ( CDView.DB_SubjectID_CD = ReqView.DB_SUbjectID )
) InterimView
ON ( InterimView.DB_FormID = TestView.DB_FormID_T AND
InterimView.DB_LabSampleID = TestView.DB_LabSampleID_T )
The above query takes abotu 8 secs to run on 2000 and about 1 minute to run on 2005. This is for a small dataset and on larger datasets this is only going to more pronounced ( as confirmed by other teams that have already migrated in my company). Another point worth mentioning might be if I remove the TestView.* from the select list, it works in 5 to 6 seconds. Is there an issue with Sql 2005 and a large number of columns or anything of that sort? On 2000, the time remains the same , about 8 seconds if I remove this from the select list.
Here is the statistics ion on 2005
(21234 row(s) affected)
Table 'Worktable'. Scan count 75490, logical reads 3676867, physical reads 0, read-ahead reads 0, lob logical reads 0, lob physical reads 0, lob read-ahead reads 0.
Table 'LabTestToReportPanel'. Scan count 476, logical reads 1524, physical reads 0, read-ahead reads 0, lob logical reads 0, lob physical reads 0, lob read-ahead reads 0.
Table 'LabReportPanel'. Scan count 0, logical reads 260, physical reads 0, read-ahead reads 0, lob logical reads 0, lob physical reads 0, lob read-ahead reads 0.
Table 'DiscreteValue'. Scan count 1, logical reads 176106, physical reads 0, read-ahead reads 0, lob logical reads 0, lob physical reads 0, lob read-ahead reads 0.
Table 'LabReleasedSampleTest'. Scan count 1, logical reads 2078, physical reads 0, read-ahead reads 0, lob logical reads 0, lob physical reads 0, lob read-ahead reads 0.
Table 'LabSample'. Scan count 1360, logical reads 18567, physical reads 0, read-ahead reads 0, lob logical reads 0, lob physical reads 0, lob read-ahead reads 0.
Table 'Form'. Scan count 2302, logical reads 8225, physical reads 0, read-ahead reads 0, lob logical reads 0, lob physical reads 0, lob read-ahead reads 0.
Table 'LabTest'. Scan count 1, logical reads 23, physical reads 0, read-ahead reads 0, lob logical reads 0, lob physical reads 0, lob read-ahead reads 0.
Table 'LabSampleDef'. Scan count 1, logical reads 10530, physical reads 0, read-ahead reads 0, lob logical reads 0, lob physical reads 0, lob read-ahead reads 0.
Table 'LabArea'. Scan count 1, logical reads 2, physical reads 0, read-ahead reads 0, lob logical reads 0, lob physical reads 0, lob read-ahead reads 0.
Table 'Lab'. Scan count 1, logical reads 2, physical reads 0, read-ahead reads 0, lob logical reads 0, lob physical reads 0, lob read-ahead reads 0.
Table 'Location'. Scan count 1, logical reads 2, physical reads 0, read-ahead reads 0, lob logical reads 0, lob physical reads 0, lob read-ahead reads 0.
Table 'Study'. Scan count 0, logical reads 6, physical reads 0, read-ahead reads 0, lob logical reads 0, lob physical reads 0, lob read-ahead reads 0.
Table 'Item'. Scan count 1335, logical reads 32940, physical reads 0, read-ahead reads 0, lob logical reads 0, lob physical reads 0, lob read-ahead reads 0.
Table 'ObjectState'. Scan count 1, logical reads 10972, physical reads 0, read-ahead reads 0, lob logical reads 0, lob physical reads 0, lob read-ahead reads 0.
Table 'Object'. Scan count 0, logical reads 20674, physical reads 0, read-ahead reads 0, lob logical reads 0, lob physical reads 0, lob read-ahead reads 0.
Table 'Subject'. Scan count 0, logical reads 3293, physical reads 0, read-ahead reads 0, lob logical reads 0, lob physical reads 0, lob read-ahead reads 0.
Table 'FormDef'. Scan count 2, logical reads 70, physical reads 0, read-ahead reads 0, lob logical reads 0, lob physical reads 0, lob read-ahead reads 0.
Table 'PrintedLabSampleLabel'. Scan count 0, logical reads 13144, physical reads 0, read-ahead reads 0, lob logical reads 0, lob physical reads 0, lob read-ahead reads 0.
Table 'PrintedForm'. Scan count 0, logical reads 4219, physical reads 0, read-ahead reads 0, lob logical reads 0, lob physical reads 0, lob read-ahead reads 0.
Table 'StudySite'. Scan count 0, logical reads 2756, physical reads 0, read-ahead reads 0, lob logical reads 0, lob physical reads 0, lob read-ahead reads 0.
Table 'StudyEvent'. Scan count 18, logical reads 40, physical reads 0, read-ahead reads 0, lob logical reads 0, lob physical reads 0, lob read-ahead reads 0.
Table 'StudyEventDef'. Scan count 0, logical reads 36, physical reads 0, read-ahead reads 0, lob logical reads 0, lob physical reads 0, lob read-ahead reads 0.
Table 'FormDefToStudyEventDef'. Scan count 1, logical reads 43, physical reads 0, read-ahead reads 0, lob logical reads 0, lob physical reads 0, lob read-ahead reads 0.
Table 'LabSampleDefToFormDef'. Scan count 1, logical reads 255, physical reads 0, read-ahead reads 0, lob logical reads 0, lob physical reads 0, lob read-ahead reads 0.
Here is the statistics ion on 2000
Table 'LabTestToReportPanel'. Scan count 2123, logical reads 4820, physical reads 44, read-ahead reads 0.
Table 'LabReportPanel'. Scan count 130, logical reads 260, physical reads 0, read-ahead reads 0.
Table 'DiscreteValue'. Scan count 103914, logical reads 208214, physical reads 0, read-ahead reads 0.
Table 'Location'. Scan count 19031, logical reads 38062, physical reads 2, read-ahead reads 0.
Table 'Lab'. Scan count 19031, logical reads 38062, physical reads 0, read-ahead reads 0.
Table 'LabArea'. Scan count 19031, logical reads 38062, physical reads 0, read-ahead reads 0.
Table 'LabSampleDef'. Scan count 24670, logical reads 49340, physical reads 0, read-ahead reads 0.
Table 'LabTest'. Scan count 19406, logical reads 39575, physical reads 0, read-ahead reads 0.
Table 'LabReleasedSampleTest'. Scan count 4289, logical reads 73865, physical reads 1014, read-ahead reads 24.
Table 'Study'. Scan count 4291, logical reads 8582, physical reads 0, read-ahead reads 0.
Table 'LabSample'. Scan count 5647, logical reads 31382, physical reads 308, read-ahead reads 4.
Table 'Form'. Scan count 4291, logical reads 9272, physical reads 2, read-ahead reads 10.
Table 'PrintedLabSampleLabel'. Scan count 4289, logical reads 17097, physical reads 114, read-ahead reads 308.
Table 'ObjectState'. Scan count 6860, logical reads 13760, physical reads 1, read-ahead reads 0.
Table 'Object'. Scan count 6860, logical reads 23559, physical reads 90, read-ahead reads 701.
Table 'PrintedForm'. Scan count 1375, logical reads 4505, physical reads 40, read-ahead reads 16.
Table 'StudySite'. Scan count 1378, logical reads 2756, physical reads 4, read-ahead reads 0.
Table 'Subject'. Scan count 1599, logical reads 3332, physical reads 2, read-ahead reads 0.
Table 'StudyEvent'. Scan count 18, logical reads 52, physical reads 0, read-ahead reads 0.
Table 'StudyEventDef'. Scan count 18, logical reads 54, physical reads 0, read-ahead reads 2.
Table 'FormDefToStudyEventDef'. Scan count 1, logical reads 69, physical reads 0, read-ahead reads 23.
Table 'FormDef'. Scan count 2, logical reads 78, physical reads 1, read-ahead reads 4.
Table 'LabSampleDefToFormDef'. Scan count 1, logical reads 308, physical reads 1, read-ahead reads 306.
Table 'Item'. Scan count 1335, logical reads 36510, physical reads 140, read-ahead reads 1047.
(21234 row(s) affected)
(147 row(s) affected)
One difference between the two is the work table that 2005 creates versus 2000. I can attach the plans but they are huge. I will attach it if you ask.
What I was looking for was suggestions on what I could do short of rewriting code or any suggestions in general.
FYI, this has also been posted on the SQL Server Engine forum.
Thanks
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