Usage Cindex Slower That Index?
Sep 3, 2004
I've got a table with a pk (bigint, no autoincrement) that has a clustered index. Same table has an integer field with a non-unique index on it.
When I do a count(*) on the table, the non-unique index is used (20m rows, 12 secs). When I force the count(*) to use the clustered index, it takes 43 secs. When selecting rows, usually the clustered index is used.
So I'm curious as to why the count(*) uses the non-unique index and the others don't. I've noticed it's faster but, why? Any ideas/considerations?
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Oct 19, 2014
why index reorganizing is 10 times slower then rebuild with "ONLINE=ON" clause?
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Jul 20, 2005
I am begginner at best so I hope someone that is better can help.I have a stored procedure that updates a view that I wrote using 2cursors.(Kind of a Inner Loop) I wrote it this way Because I couldn'tdo it using reqular transact SQL.The problem is that this procedure is taking longer and longer to run.Up to 5 hours now! It is anaylizing about 30,000 records. I thinkpartly because we add new records every month.The procedure works like this.The first Cursor stores a unique account and duedate combination fromthe view.It then finds all the accts in the view that have that account duedatecombo and loads them into Cursor 2 this groups them together for datamanipulation. The accounts have to be grouped this way because aaccount can have different due dates and multiple records within eachaccount due date combo and they need to be looked at this way aslittle singular groups.Here is my procedure I hope someone can shead some light on this. Myboss is giving me heck about it. (I think he thinks Girls cant code!)I got this far I hope someone can help me optimize it further.CREATE PROCEDURE dbo.sp_PromiseStatusASBEGINSET NOCOUNT ON/* Global variables */DECLARE @tot_pay moneyDECLARE @rec_upd VARCHAR(1)DECLARE @todays_date varchar(12)DECLARE @mActivityDate2_temp datetimeDECLARE @tot_paydate datetime/* variables for cursor ACT_CUR1*/DECLARE @mAcct_Num1 BIGINTDECLARE @mDueDate1 datetime/* variables for ACT_CUR2 */DECLARE @mAcct_Num2 BIGINTDECLARE @mActivity_Date2 datetimeDECLARE @mPromise_Amt_1 moneyDECLARE @mPromise_Status varchar(3)DECLARE @mCurrent_Due_Amt moneyDECLARE @mDPD intDECLARE @mPromise_Date datetimeSELECT @todays_date =''+CAST(DATEPART(mm,getdate()) AS varchar(2))+'/'+CAST(DATEPART(dd,getdate()) AS varchar(2))+'/'+CAST(DATEPART(yyyy,getdate()) AS varchar(4))+''DECLARE ACT_CUR1 CURSOR FORSELECT DISTINCTA.ACCT_NUM,A.DUE_DATEFROM VWAPPLICABLEPROMISEACTIVITYRECORDS AOPEN ACT_CUR1FETCH NEXT FROM ACT_CUR1 INTO @mAcct_Num1 , @mDueDate1WHILE (@@FETCH_STATUS = 0)BEGINSELECT @rec_upd = 'N 'DECLARE ACT_CUR2 CURSOR FORSELECTB.ACCT_NUM,B.ACTIVITY_DATE,B.PROMISE_AMT_1,B.PROMISE_STATUS,B.CURRENT_DUE_AMT,B.DAYS_DELINQUENT_NUM,B.PROMISE_DATE_1FROM VWAPPLICABLEPROMISEACTIVITYRECORDS B (UPDLOCK)WHERE B.ACCT_NUM = @mAcct_Num1ANDB.DUE_DATE = @mDueDate1ORDER BY B.ACCT_NUM,B.DUE_DATE,B.ACTIVITY_DATE,CASEB.Time_ObtainedWHEN 0 THEN 0ELSE 1END Desc, B.Time_ObtainedOPEN ACT_CUR2FETCH NEXT FROM ACT_CUR2INTO @mAcct_Num2 ,@mActivity_Date2,@mPromise_Amt_1,@mPromise_Status ,@mCurrent_Due_Amt,@mDPD,@mPromise_DateWHILE (@@FETCH_STATUS = 0)BEGIN----CHECK------------------------------------------------------------------------DECLARE @PrintVariable2 VARCHAR (8000)--SELECT @PrintVariable2 = CAST(@MACCT_NUM2 AS VARCHAR)+''+CAST(@MACTIVITY_DATE2 AS VARCHAR)+' '+CAST(@MPROMISE_AMT_1 ASVARCHAR)+' '+CAST(@MPROMISE_STATUS AS VARCHAR)+''+CAST(@mCurrent_Due_Amt AS VARCHAR)+' '+CAST(@mDPD AS VARCHAR)+''+CAST(@mPromise_Date AS VARCHAR)--PRINT @PrintVariable2----ENDCHECK------------------------------------------------------------IF @mDPD >= 30BEGINSELECT @tot_pay = SUM(CONVERT(FLOAT, C.PAY_AMT))FROM vwAplicablePayments CWHERE C.ACCT_NUM = @mAcct_Num2ANDC.ACTIVITY_DATE >= @mActivity_Date2ANDC.ACTIVITY_DATE < @mActivity_Date2 + 15----CHECK------------------------------------------------------------------------DECLARE @PrintVariable3 VARCHAR (8000)--SELECT @PrintVariable3 ='Greater=30 DOLLARS COLLECTED'--PRINT @PrintVariable3----ENDCHECK------------------------------------------------------------ENDELSE IF @mDPD < 30BEGINSELECT @tot_pay = SUM(CONVERT(FLOAT, C.PAY_AMT))FROM vwAplicablePayments CWHERE C.ACCT_NUM = @mAcct_Num2ANDC.ACTIVITY_DATE >= @mActivity_Date2ANDC.ACTIVITY_DATE BETWEEN @mActivity_Date2 AND@mPromise_Date + 5----CHECK----------------------------------------------------------------------DECLARE @PrintVariable4 VARCHAR (8000)--SELECT @PrintVariable4 ='Less 30 DOLLARS COLLECTED'--PRINT @PrintVariable4----END CHECK------------------------------------------------------------END----------------------------------------MY REVISEDLOGIC-------------------------------------------------------IF @rec_upd = 'N'BEGINIF @mDPD >= 30BEGINSELECT @mActivityDate2_temp = @mActivity_Date2 + 15--DECLARE @PrintVariable5 VARCHAR (8000)--SELECT @PrintVariable5 =' GREATER= 30 USING ACTVITY_DATE+15'--PRINT @PrintVariable5ENDELSE IF @mDPD < 30BEGINSELECT @mActivityDate2_temp = @mPromise_Date + 5--DECLARE @PrintVariable6 VARCHAR (8000)--SELECT @PrintVariable6 =' LESS 30 USING PROMISE_DATE+5'--PRINT @PrintVariable6ENDIF @tot_pay >= 0.9 * @mCurrent_Due_Amt--used to be promise amtBEGINUPDATE VWAPPLICABLEPROMISEACTIVITYRECORDSSET PROMISE_STATUS = 'PK',TOTAL_DOLLARS_COLL = @tot_payWHERE CURRENT OF ACT_CUR2--This statement updates the time that the status was placedinto PK.IF @mPromise_Status IN ('PTP','OP')BEGINUPDATE VWAPPLICABLEPROMISEACTIVITYRECORDSSET Status_Date = @todays_dateWHERE CURRENT OF ACT_CUR2ENDSELECT @rec_upd = 'Y 'ENDIF ((@tot_pay < 0.9 * @mCurrent_Due_Amt) OR @tot_pay IS NULL)AND( @mActivityDate2_temp > @todays_date )--need to put 1dayof month here for snapshot9/01/2004BEGINUPDATE VWAPPLICABLEPROMISEACTIVITYRECORDSSETPROMISE_STATUS = 'OP'WHERE CURRENT OF ACT_CUR2--This statement updates the time that the status was placedinto OP which is the original Activity Date.--The record will hold this date until it goes into PK,PB,orIP.IF @mPromise_Status IN ('PTP','OP')BEGINUPDATE VWAPPLICABLEPROMISEACTIVITYRECORDSSET Status_Date = @mActivity_Date2WHERE CURRENT OF ACT_CUR2ENDENDELSE IF ((@tot_pay < 0.9 * @mCurrent_Due_Amt) OR @tot_pay ISNULL)AND( @mActivityDate2_temp <= @todays_date )--need to put 1dayof month here for snapshot 9/01/2004BEGINUPDATE VWAPPLICABLEPROMISEACTIVITYRECORDSSETPROMISE_STATUS = 'PB',TOTAL_DOLLARS_COLL = case when @tot_pay is nullthen 0 else @tot_pay endWHERE CURRENT OF ACT_CUR2--This statement updates the time that the status was placedinto PB.IF @mPromise_Status IN ('PTP','OP')BEGINUPDATE VWAPPLICABLEPROMISEACTIVITYRECORDSSET Status_Date = @todays_dateWHERE CURRENT OF ACT_CUR2ENDENDENDELSE IF @rec_upd = 'Y'BEGINUPDATE VWAPPLICABLEPROMISEACTIVITYRECORDSSETPROMISE_STATUS = 'IP',TOTAL_DOLLARS_COLL = 0WHERE CURRENT OF ACT_CUR2--This statement updates the time that the status was placedinto IP.IF @mPromise_Status NOT IN ('IP')BEGINUPDATE VWAPPLICABLEPROMISEACTIVITYRECORDSSET Status_Date = @todays_dateWHERE CURRENT OF ACT_CUR2ENDENDFETCH NEXT FROM ACT_CUR2 INTO @mAcct_Num2,@mActivity_Date2,@mPromise_Amt_1,@mPromise_Status ,@mCurrent_Due_Amt,@mDPD,@mPromise_DateENDCLOSE ACT_CUR2DEALLOCATE ACT_CUR2FETCH NEXT FROM ACT_CUR1 INTO @mAcct_Num1 , @mDueDate1ENDCLOSE ACT_CUR1DEALLOCATE ACT_CUR1SET NOCOUNT OFFENDGO
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Aug 24, 2000
Hi all,
I need to drop some of my indexes to keep the size of my DB manageable. I know they're not all being used, but what is the best way to determine how often they are being used? Statistics? I haven't come across any text referring to this so any help is appreciated.
Pete Karhatsu
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Aug 14, 2007
Does SQL Server store somewhere (in a table that I can query) when last an index was used by any queries?
Or does it store which query plans it's a part of?
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Sep 27, 2007
Hi all,
When i execute the following query on my database, to see the index usage information,
-------------------------------------------------------------------------------------------
use databasenamego
SELECT OBJECT_NAME(S.[OBJECT_ID]) AS [OBJECT NAME], I.[NAME] AS [INDEX NAME],
USER_SEEKS, USER_SCANS,
USER_LOOKUPS,
USER_UPDATES FROM SYS.DM_DB_INDEX_USAGE_STATS AS S
INNER JOIN SYS.INDEXES AS I ON I.[OBJECT_ID] = S.[OBJECT_ID]
AND I.INDEX_ID = S.INDEX_ID
WHERE OBJECTPROPERTY(S.[OBJECT_ID],'IsUserTable') = 1
-----------------------------------------------------------------------------------------
I see for some indexes, the columsn User_seeks= 0, User_scans = 0 .
Does this mean that, those indexes are not being used .
I wanted to know, what is the best way & best criteria to look for, in order to find whether particular index is being used (or) not.( Probalby,We can use DTA , but i believe , there should some way through DMV's also)
Because by keeping unncessary indexes, performance can be hammered on a table whose size is 170 Gb with 9 Non-clustered indexes , 1 clustered
Need some advice on this.
Thanks..
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Oct 17, 2007
I am looking for some expert opinions on when is it not appropriate to use a clustered index on a table?
Future guru in the making.
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Nov 18, 2004
I'm trying to establish the mb usage of a series of nonclustered indexes, I'm used to using the manage indexes GUI in 6.5, and showcontig doesn't quite give me what I want, any suggestions?
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Sep 7, 2004
Hello!
Is there any way to determine index usage statistics for a given table?
For examle, I have a table, with three indices. I need to know how many times each index was used. Is it possible?
And second part of question: I need to know, which user overloads my base with their giantic queries. Is there any way to determine, how many system resources each of user's sessions uses?
MS SQL Server 2000 Enterprise Edition.
Thank you!
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Sep 13, 2004
Can anyone tell me a good way to monitor which indexes are not being used? Over time, I'm sure there are extraneous indexes in our database, which I would like to get rid of.
Any ideas would be appreciated.
Thanks,
Rob
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May 22, 2007
We're using slowly changing dimensions to control a number of data tables in our system. Each table has five or six business keys, but the indexes of the tables are built so they're as efficient as possible (i.e. the fields with the highest diversity are listed first). How does the SCD wizard determine the order of the business key fields? Is there a way I can view or manipulate the statement the SCD task is using to make sure either (a) the indexes match the statement, or (b) the statement matches the indexes?
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Jul 25, 2007
Hi guys,
My company is currently migrating from Interbase to SQL Server 2005. During the migration we have came across a rather peculiar issue and wondering if anyone can advise.
We have a table.. named "prospect" which holds client information
We have a stored procedure which hangs on the following statement.
DECLARE @surname char(25);
SET @surname='BLAH%';
SELECT *
FROM Prospect
WHERE c_surname LIKE @surname;
The above takes 28 seconds to run. The following statement returns a result inside a second.
SELECT *
FROM Prospect
WHERE c_surname LIKE 'BLAH%';
In Interbase, the original returned the answer within a second too. The schema in both database is the same.
The 1st statement does not use an index! The execution plan is different to the 2nd statement. I am aware I can create an index recommended by the Database Engine Tuning which solves the issue or specify the index to use in the original statement but why does the engine not use the correct index if there is a variable involved? I need to know as we have just started looking at the code.
Thanks,
Kalim
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Mar 1, 2008
hi, friends, please look at this:
I have a SSIS package, and inside it I do something like below:
1. I have a SQL component, to give back a object to store the records.
2. I have a VB script component, I direct the object I got in 1 step into the script as a dataset.
My problem is:
I run the package in the SQL SERVER 2005 Store Procedue like this:
do
dtexec.exe package.dtsx
loop untill i>t
I control the it runs 30 times. But I found that the speed is slower and slower.
the first time, it takes about 600 s, but the last time, it takes the 1800 s.
Why?
The package don't drop the object it create during the loop in the Store Procedue ?
Thanks!
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Oct 4, 2015
I want to create a lot of index for my database for performance.
But I need find memory usage by indexes.
How to find memory usage by index in sql server?
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Oct 4, 2015
i want to create a lot of index for my database for performance.but i need find memory usage by indexes.
How to find memory usage by index in sql server?
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Nov 2, 2007
I have a client program that writes to sql server database 10 records per second . i want to compute the CPU usage and the memory usage for the whole program or CPU usage,memory usage for the insert statement in the program .
Can anybody help me with this?
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Sep 7, 2007
Hello, When I am seeing SQL Server 2005 Management studio Server Dashboard> I am seeing my(USERS) databases and msdb database usage is very small % of in CPU Usage(%), Logical IO Performed (%) Usage pie chart.
90% of Total cpu usage is showing for Adhoc Queries. what excatly this means in Dashboard? if application uses more than it would have shown in Database level or not?
sicerely this dashboard is good, if any one is watching daily, please advice their experiences here.
Thanks in advance. Hail SQL Server!
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Oct 20, 2006
please explain the differences btween this logical & phisicall operations that we can see therir graphical icons in execution plan tab in Management Studio
thank you in advance
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Jan 30, 2014
providing a query for fetching the data for CPU Usage, Memory usage, blocking and all details ...
I want to create a job which will run on a Node every 15 min and store data in a table for each instance...
DMV is not giving more stuff and xtended events not sure if i can store that data into a table?
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Mar 22, 2007
I am not sure if this is the correct forum but here goes!
We rebuilt our SqlServer 2000 Trans replication the other night. It used to run in 3 hours but now it runs in 9.5 hours (7 hours bcp out, 2.5 hours bcp in). We have a dedicated distributor box (4 processors), a 4 processor publisher, and a 2 processor subscriber. None of the systems exhibited any processor stress or unusual disk activity. The network tests OK (tested with file xfers). But the bcp's wrote data at 2.5 to 4 minutes per 100k rows, and they loaded the data at about 100k rows in 10 seconds or less.
As you know, Replication Snapshot uses bcp on each source table to build a collection of flat-files. Then it uses bcp to load those files into the subscribing tables. Because bcp is the workhhorse here, I decided against posting this in the Replication forum.
The only change I know of is increasing MaxBcpThreads from 4 to 8. This parameter specifies the number of bulk-copy operations that can be performed in parallel. I was thinking that 8 bcp's might somehow be killing the drive where all the bcp files are written.
Any ideas?
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Apr 12, 2007
I installed SP2 two days ago and it seems like my SSIS-packes now take longer time than before - the very opposite of what I was hoping for.
Anyway, here are some data from runs on our performance environment. No new data is added to the source database between the runs, but I do a full process of the cubes every time (time is in seconds):
Package...............................SP1...............................SP2
Load dimensions..................200.................................270
Load fact data.......................800...............................1600
Process cubes....................2100...............................2600
So, as you can see, everything is going slower with SP2. I have yet to look into if there are any specific steps in the packages that take longer time than before, but it's odd that all packages take a longer time to execute. Especially that cube processing is slower suprises me.
Has anyone experienced something similar? Thanks!
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Nov 14, 2000
Hi gurus
I haven't put the code in since I've tried several variations & keep having the same problem: I'm hoping someone will recognise the problem from a description of it.
There are two parts to my query.
* Part 1 creates and then populates a temporary table
* Part 2 is a select query which joins the temporary table to a permanent table, on 2 fields including a datetime field. The data types on each side of the join are identical.
If I run the first part of the query through ISQL and wait for it to complete before running the second part (in the same ISQL window), it (the second part) takes just 3 minutes. However, if I run both parts together, the second part takes ages, in fact I'm not sure if it completes at all (could wait indefinately!).
I tried placing a 'GO' between the two queries when running them together, but it didn't seem to help.
Please help, I'm stumped.
Thanks
Jo
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Oct 13, 2004
I have database, Visual basic as front end, and sql server as backend, the reports are using crystal report. Recently, the user complain it is too slow to run, it took a long to load the data, anybody help me? Thanks in advance.
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Oct 29, 2005
I am new to SSIS and probably doing some mistake while transferring data from oracle source to oracle destination. Please guide me.. In our project we need to transfer nearly 80 GB data from old system (Oracle 9i) to new system (Oracle 10 G Release 2). To do this exercise we are testing and comparing performance and cost effectiveness between different tools like SSIS, DTS and SQL * Loader (oracle built in tool). We have selected one table, which is having 40 fields with 3 million records. The destination table is also having same structure. Surprisingly SSIS is giving slower performance than DTS!!!!! It is taking more than two hours or nearly two hours. I have tested the same process 3 times. I have used two servers (1 GB RAM, Dual processor) for source and destination with minimum load and used data flow task (OLEDB Source and OLEDB Destination). In case of transferring data from Oracle to SQL SERVER I am finding €śFast Loading Option€? in data access mode, which is giving considerable performance boosting. But while transferring data from Oracle to Oracle I am not finding €śFast Loading Option€? !!!!!!!!! For performance boosting which provider I should use?? Please suggest me€¦ if any one can€¦ would remain grateful to him€¦ Thanks and Regards Sudripta Rakshit.
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Jan 14, 2008
I copied a code from one proc and created new proc with the same code but different name. Using the same parameter for both procedures I got the different time of execution. New one is 4 times slower. I went through execution plan and could not find any changes. Does anyone have any experiance like this?
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Feb 2, 2007
Hi,We have a C# web application that has been running for a few years now with little maintenance. Over the past few months, we have had some increasing problems.1. Loses session frequently ~ every 2-3 minutes.2. Occasionally (every 2 months) get out of memory exceptions.3. Connections to the DB and therefore the whole site run fast after restart. Gets continuously slower and slower over time until it starts throwing timeouts: System.Data.SqlClient.SqlException: Timeout expired. The timeout period elapsed
prior to completion of the operation or the server is not responding. The timeouts usually come every 3 weeks or so. Number 3 is the biggest problem for us, but I thought maybe 1 or 2 give some indication to why 3 is happening?I don't have much time to look into this now as I'm working on another project, but I was hoping that maybe someone would have ideas just looking at our symptoms.Thank you so much,Christie
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May 3, 2001
I know this won't be a lot to go on but, we has a quad processor box that is doing a lot of sql crunching. When we turn off three of the processors it runs the SQL queries faster. The requests are comming from COM objects. CPU, Memory, page faults, all that stuff is fine. Also SQL dosen't appear to be using all the processors as only 1 has any amount of usage?. Any suggestions of where to start would be most appreaciated.
Mike
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Jun 12, 2002
Ok,
here's a funky one That I can't find an expanation for. If I go into EM and choose a table from a database and return all rows, I get immediate results and can start browsing records. If I go into query analyzer and do a select * on the same table, it takes up to 20-25 minutes to return the result set. This used to only take like 5 mins. What gives? Anyone seen this before?
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Aug 24, 2004
I have an issue with the BCP util, it is extremely slow when running a BCP in to the same database on an A/P cluster vs. Standalone system. It is a vendor application, so I have little control as to what I can do. The BCP runs from a jobserver (remote) through the network, but it runs the same way in the standalone system, yet the process is about 10X as slow with the cluster, and the only diff is cluster vs. standalone.
SQLClusterName is specified in -S, not the active node, and it uses a trusted connection, not a local account. Is there anything about a cluster config that would cause the BCP to run slower ?
Any thoughts ??
Thanks,
Paul
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Mar 29, 2007
Hi there,
I am an application programmer who uses SQL Server; I'm not an expert and just know the basics. Our application has approximately 300 SQL tables and each table has just one primary index. We don't have stored procedures and only have 3 Views that a couple of reports use. Our database is approximately 26GB in size. We are planning on migrating from SQL 2000/Windows Server 2000 to SQL 2005/Windows Server 2003. Before doing this I decided to do some bench mark testing. I chose a simple SELECT statement on one of our larger tables. On SQL 2000 it ran in 22 seconds whereas on SQL 2005 it ran in 34 seconds.
These are the steps I have done to try and improve performance, all to no avail.
I tried both a passive and active upgrade and the results were the same. The passive way was to remove 2000, install 2005, create a new database and restore from a 2000 backup into the new 2005 database. The active way was to leave 2000 on the server with the database attached and upgrading to 2005.
I did not change any defaults on the database except I have set the compatibility level to SQL 2005.
The collation is set to SQL_Latin1_General_CP1_CS_AS.
I have run an Optimize Index Task.
I have run a Rebuild Index Task.
I have run an Update Statistics Task.
I have defragged the drive that the database resides on.
Can anyone explain why SQL 2003 is dramatically slower than 2000? Any help would be greatly appreciated.
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Mar 29, 2007
Hi there,
I am an application programmer who uses SQL Server; I'm not an expert and just know the basics. Our application has approximately 300 SQL tables and each table has just one primary index. We don't have stored procedures and only have 3 Views that a couple of reports use. Our database is approximately 26GB in size. We are planning on migrating from SQL 2000/Windows Server 2000 to SQL 2005/Windows Server 2003. Before doing this I decided to do some bench mark testing. I chose a simple SELECT statement on one of our larger tables. On SQL 2000 it ran in 22 seconds whereas on SQL 2005 it ran in 34 seconds.
These are the steps I have done to try and improve performance, all to no avail.
I tried both a passive and active upgrade and the results were the same. The passive way was to remove 2000, install 2005, create a new database and restore from a 2000 backup into the new 2005 database. The active way was to leave 2000 on the server with the database attached and upgrading to 2005.
I did not change any defaults on the database except I have set the compatibility level to SQL 2005.
The collation is set to SQL_Latin1_General_CP1_CS_AS.
I have run an Optimize Index Task.
I have run a Rebuild Index Task.
I have run an Update Statistics Task.
I have defragged the drive that the database resides on.
Can anyone explain why SQL 2003 is dramatically slower than 2000?
Any help would be greatly appreciated.
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Jul 23, 2005
-- I have a situation where doing-- first example-- 1. Get series of values througha query into a string (@val)like'1,2,3,4':declare @val varchar(4000)select @Val = @val + cast(myval as varchar) + ',' -- myval is aninteger variablefrom xyzwhere xyz.field = 33SET @val = left(@val, len(@val) - 1)-- 2. EXEC a query using IN (' + @val + ')'EXEC('select *from qprwhere qpr.fieldx IN (' + @val + ')')-- is much faster than doing-- second exampleselect *from qprwhere qpr.fieldx IN (select myvalfrom xyzwhere xyz.field = 33)-- Since second example does not have a correlateed query, why is itslower?-- Thanks in advance,-- Caveman
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Mar 29, 2007
Hi there,
I am an application programmer who uses SQL Server; I'm not an expert and just know the basics. Our application has approximately 300 SQL tables and each table has just one primary index. We don't have stored procedures and only have 3 Views that a couple of reports use. Our database is approximately 26GB in size. We are planning on migrating from SQL 2000/Windows Server 2000 to SQL 2005/Windows Server 2003. Before doing this I decided to do some bench mark testing. I chose a simple SELECT statement on one of our larger tables. On SQL 2000 it ran in 22 seconds whereas on SQL 2005 it ran in 34 seconds.
These are the steps I have done to try and improve performance, all to no avail.
I tried both a passive and active upgrade and the results were the same. The passive way was to remove 2000, install 2005, create a new database and restore from a 2000 backup into the new 2005 database. The active way was to leave 2000 on the server with the database attached and upgrading to 2005.
I did not change any defaults on the database except I have set the compatibility level to SQL 2005.
The collation is set to SQL_Latin1_General_CP1_CS_AS.
I have run an Optimize Index Task.
I have run a Rebuild Index Task.
I have run an Update Statistics Task.
I have defragged the drive that the database resides on.
Can anyone explain why SQL 2003 is dramatically slower than 2000? Any help would be greatly appreciated.
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