SELECT DocID, IsRecord FROM DocTable WHERE Title LIKE '%process%'
it takes about 23 seconds to return the 481 hits.
The execution plan shows a non-clustered index scan being performed on
the Title index (returning 481 rows) and a non-clustered index scan on
the IsRecord index (returning 4.9 million rows). These are then merged
in a hash match/inner join operation.
The Title index scan has an estimated row size of 41 and an I/O cost
of 9.82 (cost is 27%). The IsRecord index scan has an estimated row
size of 33 and an I/O cost of 6.32 (cost is 21%). The Hash Match
accounts for a further 52% of the cose with the SELECT at the head of
the plan listed as 0% cost.
If I issue the following query:
SELECT DocID, Title FROM DocTable WHERE Title LIKE '%process%'
it takes about 12 seconds to return the 481 hits and consists solely
of a non-clustered index scan of the Title Index.
Again the Title index scan has an estimated row size of 41 and an I/O
cost of 9.82 ans it's cost is listed as 78%. The SELECT at the head of
the plan is attributed the other 22% of the cost.
All this is fine, however when I issue the following query:
SELECT DocID, Title, IsRecord FROM DocTable WHERE Title LIKE
'%process%'
it takes 1 minute 50 seconds to run the query. The execution plans
shows that a clustered index scan is occurring and this accounts for
96% of the cost. The estimated row size is 463 and the I/O cost is
111.
What on earth is going on here. I can understand the need to scan the
Title index because of the wildcards, but why on earth would the query
perform a scan of the clustered (primary key) index? And what is going
on with the row size and I/O cost?
All the indexes and statistics are up to date, so I am at a complete
loss to explain what is going on here. Can anyone explain why the 3rd
query is so much slower (and possibly suggest a way to improve the
performance)/
Thanks
Paul Mateer
Meridio Limted
I am at a complete loss to explain what is happening here,
If I start a long running query running on a background thread is there a way to abort the query so that it does not continue running on SQL server?
The query would be running on SQL Server 2005 from a Windows form application using the Background worker component. So the query would have been started from the background workers DoWork event using ado.net. If the user clicks an abort button in the UI I would want the query to die so that it does not continue to use sql server resources.
We have a performance problem when running a relatively heavy INSERT statement from a COM+ application against SQL Server 2005 (SP1). The query takes up all CPU resources (4 CPUs) on the database server while processing (about 15 minutes) and the database server does not respond to other queries. The general response from the database server computer is also poor, including its desktop and other user interactions.
When running the same statement from Managerment Studio, it takes about same time to complete, but it only takes up 1 CPU and other queries can run at the same time.
This happens only for some queries. A minor change to the SELECT-part of the query may make the problem go away.
The SQL Server database is a clustered 64 bit installation. The SQL Server has SP1 installed, but not SP2. Is it likely that this issue is fixed in SP2?
More information: we are running in a DTC transaction from COM+. The database are using the read committed snapshot option.
I have a question about some problems when running SQL Server 2005 together with an application on the same machine (it's a JBoss application). The machine has 3GB which is more than enough of memory for our application + SQL Server.
When our application is running I notice a very large increase in the query execution time. When the application is run on another machine though, we do not notice this slowdown.
Both SQL Server and JBoss are using a different disk. (RAID1 and RAID5 respectively).
Any help or hints where I can start to find the reason for this problem.
Hello Everyone,I have a very complex performance issue with our production database.Here's the scenario. We have a production webserver server and adevelopment web server. Both are running SQL Server 2000.I encounted various performance issues with the production server with aparticular query. It would take approximately 22 seconds to return 100rows, thats about 0.22 seconds per row. Note: I ran the query in singleuser mode. So I tested the query on the Development server by taking abackup (.dmp) of the database and moving it onto the dev server. I ranthe same query and found that it ran in less than a second.I took a look at the query execution plan and I found that they we'rethe exact same in both cases.Then I took a look at the various index's, and again I found nodifferences in the table indices.If both databases are identical, I'm assumeing that the issue is relatedto some external hardware issue like: disk space, memory etc. Or couldit be OS software related issues, like service packs, SQL Serverconfiguations etc.Here's what I've done to rule out some obvious hardware issues on theprod server:1. Moved all extraneous files to a secondary harddrive to free up spaceon the primary harddrive. There is 55gb's of free space on the disk.2. Applied SQL Server SP4 service packs3. Defragmented the primary harddrive4. Applied all Windows Server 2003 updatesHere is the prod servers system specs:2x Intel Xeon 2.67GHZTotal Physical Memory 2GB, Available Physical Memory 815MBWindows Server 2003 SE /w SP1Here is the dev serers system specs:2x Intel Xeon 2.80GHz2GB DDR2-SDRAMWindows Server 2003 SE /w SP1I'm not sure what else to do, the query performance is an order ofmagnitude difference and I can't explain it. To me its is a hardware oroperating system related issue.Any Ideas would help me greatly!Thanks,Brian T*** Sent via Developersdex http://www.developersdex.com ***
Does anyone out there know if you can take a user like this domain1Username and without dropping it and recreating change it to domain2username. I am using Sql 7.
So, I kinda taught myself sql on the net in a couple of weeks... I've been practicing commands and what not with a database with a company I work with. Here's what I need some help with:
I'm creating a batch file that will connect to the sql server, and input a .sql in the batch file which launches the sql script to check to see if a store's data has come in or not, and if it hasn't, to launch the job to process that store. Now, after it launches the job, the only step for the job is to process what it can before it fails or completes, and most of the time it fails after 1-10 minutes. A big a variance. So my question is, how do I make it so that the script being called, waits for the job to finish before proceeding to the next command which checks a different store and launches another script?
If you want the script, I'll mod out some of the actual names for security purposes and post it for you guys. Any help is appreciated, and I've searched and hacked Google to get an answer, but nothing, so I decided to post this. Thanks!
Hi everybody I want to know in the real world, what RDBMS is used for keeping people's accounts in official Banks( institution for saving and borrowing money) ? do they use SQL-Server , ORACLE or some thing else?
I created a CLR UDF that returns a large number of rows, when I run it from my VPC (XP, SQL Server Developer Edition and 1GB Memory) it takes approx 2 min and 30 secs to start displaying the rows (Using Management Studio), when I run the same query in our development server (Win 2003, SQL Server Enterprise Edition, 8 GB Memory and 8 Processors) it takes more than 15 min to start displaying the results, does anybody have an idea why is this happening?
know if running performance counters during ETL process is running will impact performance on the server, I have win 2008 r2 server with sql server 2008 r2. I want to measure performance of server while ETL is in progress.
Whilst digging about in the systables I noticed 2 curious things: When creating an application that returned all tables, columns and fields I had to use sys.systables, and when returning the information from this view, I received two identical columns 1. myColumn of type sysname and 2. myColumn of type varchar. The point being, what is this column for, and why is it there, as it was quite annoying to note it when returning the dataset in my app. My other point is, while checking out what I could do with sysname, I noted the xml type has a capacity of -1, whereas all other data types have a capacity between 2-8000. Could someone clarify this for me, as it seems a single xml document could be inserted upto 2gb. Regards.
So I have a person who is adamant in tell me that SQL Server does not run on windows XP.
Now, I have already done all the research on this (i.e. sql server 2000 product page / requirements) and know the answer, but they insist on asking the question, so here it is .....
'Will SQL Server run on Windows XP'
A simple YES or NO will suffice; however, if you want to explain the answer (if it requires one ;) ), please feel free.
Fellas!!This is a very complicated one and it took me a few days to figure outexactly what's going on, but here's the final story:I have a production environment running on .NET with a SQL Server(2000, SP3). The SQL Server is on a dedicated Proliant computer with2GB RAM (the actual SQLServer.exe process has dynamic memoryassignment and can reach up to 1.6GB RAM). Nothing else is running onthat specific computer.Once the SQLServer is started, it hits 300MB RAM (the minimum that wasset in the configuration of the server - remember, it is dynamicallyaquired).Then there is a .NET program that requests just about all the data theSQL Server contains (apart from a single table that contains roughly1.6 million rows and another table that contains about 10000 rowswhich are all of type IMAGE).Once all the data is retrieved, the RAM is at about 400MB. From thereon, every update I make to the data on the server causes the RAM to goup by a bit (that updates are done in a Transaction which of course iscommitted at the end). It seems that BLOB updates are the majorproblem in all of this. For some reason, uploading a blob of size 9MBcauses the RAM to go up by roughly 20MB and after commit it gose down10MB (total gain of roughly 10MB RAM). Eventually the SQLServerprocess hits its upper limit (1.6GB) and at this point it startsslowing down.Some performance checks showed me the SQLServer has a lot of diskactivity, it seems it is reading and writing pages of data from/to theHD all the time (which causes the queries to be much much muchslower).We have a development environment running the exact same code (it isthe exact same in everything, except for the amount of data stored inthe DB). This does not happen there at all.I have a few questions:1. Why is the RAM going up after BLOB updates?2. Why is the RAM going up at all?3. How can I tell the DB which tables should remain in the RAM at alltime (never swapped back to the HD?) - DBCC PINTABLE does not seem todo the job.It does not seem to have anything to do with the .NET code.Thank you very much,M Yamo.
Can someone try and explain to me how a sql query can run fine and return data, yet when I try to run it in dtswizard, while the "preview" view shows the data, actually running it returns zero rows?
This is on SQL2005 express and since I can't get dtsrun or dtexec to work, I'm using auto-it to simulate my actually stepping through the process. Very kludgy, but "when all you've got is a hammer...."
Dear GroupSomething that I ever found quite difficult was finding a bug in ascript e.g. in a stp#ored procedure as often it would indicate theerror in a completely different line in which the error is actuallylocated. Take the following scriptALTER PROCEDURE [dbo].[fra_UpdateCompany]@CompanyID int, @CompanyName varchar(50), @Status int, @TelNovarchar(50), @FaxNo varchar(50), @Email varchar(50), @Web varchar(50),@OfficeType int, @Comment varchar(512)ASDECLARE@CommentOrg varchar(512)IF (LEN(@CompanyName) < 1) BEGIN SET @CompanyName = NULL ENDIF (LEN(@TelNo) < 1) BEGIN SET @TelNo = NULL ENDIF (LEN(@FaxNo) < 1) BEGIN SET @FaxNo = NULL ENDIF (LEN(@Email) < 1) BEGIN SET @Email = NULL ENDIF (LEN(@Web) < 1) BEGIN SET @Web = NULL ENDIF (LEN(@Comment) < 1) BEGIN SET @Comment = NULL ENDSET @CommentOrg = (SELECT Comment from fra_company WHERE CompanyID =@CompanyID)SET @Comment = (@Comment + '' + @CommentOrg)-- UPDATE COMPANYUPDATE fra_company SET CompanyName = @CompanyName, Status = @Status,TelNo = @TelNo, FaxNo = @FaxNo, Email = @Email, Web=@Web, OfficeType =@OfficeType, Comment = LTRIM(@Comment) WHERE CompanyID = @CompanyIDIt throws an error in Line 17 IF (LEN(@TelNo) < 1) BEGIN SET @TelNo =NULL END when the error is actually in line 23: SET @CommentOrg =(SELECT Comment from fra_company WHERE CompanyID = @CompanyID)ErrorMsg:Msg 137, Level 15, State 2, Procedure fra_UpdateCompany, Line 17Must declare the scalar variable "@ContactID".Why is that? I had hoped that it had improved from SQL 7.0 to 2005 butit's still the same vague thing.Thanks for sharing your expertise and wisdom on this,Martin
Hi all I have a Float Field in my table with following values:
1.63 7.42 35.71 0.58
every thing is ok BUT when i Select Data from this table in QUERY ANALIZER environment with (Select * from mytable) , Query Analizer shows me the following values:
Dear group,if someone could give me an idea what is going on in one of ourdatabases, this would really really be helpful.We have two tables with around 2 / 3 million rows. These tables have nokey and no ID. (This major design flaw will be overcome in some laterversion of the application-software working on this DB but right now ihave to live with this).Now for the funny bit1) I open one window in the Query-Analyzer and write some code likeBegin transaction INSERT INTO TABLE COMMIT2) in another window i write "SELECT COUNT(*) from TABLE"If I perform the insert then afterwards select count(*) the row-countis incremented by two whereas the Insert-Statement said "1 row(s)modified.DBCC gives no errors.DBCC gives amount of rows 2 million rowsSelect count(*) on the same table gives 3 million rowsExporting the data, truncating the table re-importing data gives noresult, right now the DTS-status is 203 and the machine is "thinking".Is there any possibility to check the "integrity" of the table?This problem is on the production machine, but right now i am workingon a copy so it was propagated with backup / restore-mechanism.Any hint would be very helpfulThanks and GreetingsUli
I hope I am not asking about something that has been done before, but Ihave searched and cannot find an answer. What I am trying to do is torun a query, and then perform some logic on the rowcount and thenpossibly display the result of the query. I know it can be done withADO, but I need to do it in Query Analyzer. The query looks like this:select Varfrom DBwhere SomeCriteriaif @@Rowcount = 0select 'n/a'else if @@Rowcount = 1select -- this is the part where I need to redisplay the resultfrom the above queryelse if @@Rowcount > 1-- do something elseThe reason that I want to do it without re-running the query is that Iwant to minimize impact on the DB, and the reason that I can't useanother program is that I do not have a develpment environment where Ineed to run the queries. I would select the data into a temp table, butagain, I am concerned about impacting the DB. Any suggestions would begreatly appreciated. I am really hoping there is something as simple as@@resultset, or something to that effect.
I have an update query running which to just now has been running for 22 hours running on two tables 1 a lookuptable that has just been created within the batch the other a denormalised table for doing data analysis on
the query thats causing teh problem is
--//////////////////////////////////// this is the one thats running
Print 'Update Provider 04-05 EmAdmsCount12mths : ' + CAST(GETDATE() AS varchar) GO Update Provider_APC_2004_05 set EmAdmsCount12mths = (Select COUNT(*)-1 from Combined_Admissions where ((Combined_Admissions.NHSNumber = Provider_APC_2004_05.NHSNumber) or (Combined_Admissions.PASNUMBER = Provider_APC_2004_05.PDDISTNO)) and (Combined_Admissions.AdmDate BETWEEN DateAdd(yyyy,-1,Provider_APC_2004_05.AdmDate) AND Provider_APC_2004_05.AdmDate) AND Combined_Admissions.AdmMethod like 'Emergency%')-- and -- CA.NHSorPrivate = 'NHS')) FROM Provider_APC_2004_05, Combined_Admissions
any help in improving speed would be most welcome as there are 3 more of these updates to run right after this one and the analysis tables are almost double the size of this one
1) is there any way to run a query over a query without having to create a table with the results of the first query? (would drop table work? If so, how?
2) how can i define input variables the same way i do in excel? I am trying to run a couple of simulations based on 2 core inputs (in excel i would just do a data table)
Looking at BOL for temp tables help, I discover that a local temp table (I want to only have life within my stored proc) SHOULD be visible to all (child) stored procs called by the papa stored proc.
However, the following code works just peachy when I use a GLOBAL temp table (i.e., ##MyTempTbl) but fails when I use a local temp table (i.e., #MyTempTable). Through trial and error, and careful weeding efforts, I know that the error I get on the local version is coming from the xp_sendmail call. The error I get is: ODBC error 208 (42S02) Invalid object name '#MyTempTbl'.
Here is the code that works:SET NOCOUNT ON
CREATE TABLE ##MyTempTbl (SeqNo int identity, MyWords varchar(1000)) INSERT ##MyTempTbl values ('Put your long message here.') INSERT ##MyTempTbl values ('Put your second long message here.') INSERT ##MyTempTbl values ('put your really, really LONG message (yeah, every guy says his message is the longest...whatever!') DECLARE @cmd varchar(256) DECLARE @LargestEventSize int DECLARE @Width int, @Msg varchar(128) SELECT @LargestEventSize = Max(Len(MyWords)) FROM ##MyTempTbl
SET @cmd = 'SELECT Cast(MyWords AS varchar(' + CONVERT(varchar(5), @LargestEventSize) + ')) FROM ##MyTempTbl order by SeqNo' SET @Width = @LargestEventSize + 1 SET @Msg = 'Here is the junk you asked about' + CHAR(13) + '----------------------------' EXECUTE Master.dbo.xp_sendmail 'YoMama@WhoKnows.com', @query = @cmd, @no_header= 'TRUE', @width = @Width, @dbuse = 'MyDB', @subject='none of your darn business', @message= @Msg DROP TABLE ##MyTempTbl
The only thing I change to make it fail is the table name, change it from ##MyTempTbl to #MyTempTbl, and it dashes the email hopes of the stored procedure upon the jagged rocks of electronic despair.
Any insight anyone? Or is BOL just full of...well..."stuff"?
Hi guys. I'm looking for help to run a query that should come out looking like this
unit reports_to
Development Dept Representative Div Systems Group Development Dept Design Section Systems Group Production Spec Section Systems Group Proposal Section Systems Group
I can't see any way of doing this query though I know the PARENT is the reports_to column and that the UNITNO is the Department but can't find any way to run the query. Hoping you guys can help
Presumably, an RDL data set is only queried once before generating a report. And presumably, this is true even if the data set feeds a list control. However, I'd like to know if I can cause a data set to be queried repeatedly from a list control. I need to do this, because the data set contains aggregate functions that would be impacted by each "pass" the list control would make.
Is it possible to make a data set queried repeatedly in this fashion?
Is there any specific place where I can find which SQL Query is more efficient?.
Is INNER JOIN is faster or Select ... Where ID in (SELECT ...) is faster?
I have two tables: 1.FLEET (The number of rows is not so much) Attributes : Company_Id (PK) Fleet_Id (PK) Fleet_Name Fleet_Description
2.USER_PRIVILEGE (The number of rows can reach up to 3 times the number of row in fleet table) Attributes : Company_Id (PK) Fleet_Id (PK) User_Id (PK) Privilege_Id(PK) Comment Category
I want to select Fleet_Id and Fleet_Name from fleet table Where the current user has privilege_id=1
I have two possible select statement :
1.Option 1
SELECT Fleet_Name, Fleet_Id FROM FLEET WHERE (Company_Id = 2) AND (Fleet_Id IN (SELECT fleet_id FROM user_privilege WHERE user_id = 11 AND company_id = 2 AND privilege_id = 1)) ORDER BY Fleet_Name
2.Option 2
SELECT F.Fleet_Name, F.Fleet_Id FROM USER_PRIVILEGE U INNER JOIN FLEET F ON U.Fleet_Id = F.Fleet_Id WHERE (F.Company_Id = 2) AND (U.Privilege_Id = 1) AND (U.User_Id = 11) ORDER BY F.Fleet_Name
Actually which one is faster. Is SQL Statement with INNER JOIN (Option 2) can be executed faster than the one with double Select Statement(Option 1)?
Hi: I have the following query, can somebody help me? SELECT s.Id, s.NameFROM Switch s INNER JOIN SwitchTelephoneRange r ON s.Id = r.IdWHERE '1526858' BETWEEN FromTelephone AND ToTelephone Where the '1526858' is a phone number. My problem is, I want to run the above query for each record in : select Telephone from PhoneDirectory So, each telephone number in the second phone, would macth the ' ' in the first query. How can I do so? Do I need a loop? a cursor? Can you help please? Thanks
Hi, I want to know query execution time as output. I want execution time only. this is for tuning purpose... Time displayed in the status bar is not helpful for me. thanks.
Hi there, I'm having a big performance problems with sql query. What i have done is changes physical layout (rearanged the columns) in one of the tables in the database. I used bcp to get the data out and then in. There are about quarter million rows in the this table. I have created the same indexes but know the same query takes a long time to execute. I have noticed that the showplan is somehow different than it used to be. This query uses the table i have changed and another one that i haven't touched. I have updated the stats to no help. Here are the show plans. this one is slow STEP 1 The type of query is INSERT The update mode is direct Worktable created for ORDER BY FROM TABLE SW_PERSON Nested iteration Index : swiPERSON10 FROM TABLE SW_CASE Nested iteration Table Scan TO TABLE Worktable 1 STEP 2 The type of query is SELECT This step involves sorting FROM TABLE Worktable 1 Using GETSORTED Table Scan
this one used to be fast STEP 1 The type of query is INSERT The update mode is direct Worktable created for ORDER BY FROM TABLE SW_CASE Nested iteration Table Scan FROM TABLE SW_PERSON Nested iteration Index : PK_SW_PERSON_1__27 TO TABLE Worktable 1 STEP 2 The type of query is SELECT This step involves sorting FROM TABLE Worktable 1 Using GETSORTED Table Scan
I think the problem is with the fact that the fist one doesn't use the PK key which is the one the links both tables. My question is how to force the query to use this index. PS. One thing i haven't done is to recreate indexes on the other table. But i don't think that would have made a differnece. Thanks
CREATE FUNCTION dbo.fnProductsRetrieveBySupplierID ( @SupplierID int ) RETURNS TABLE AS RETURN ( SELECT * FROM Products WHERE SupplierID = @SupplierID )
CREATE FUNCTION dbo.fnSuppliersRetrieveBySupplierID ( @SupplierID int ) RETURNS TABLE AS RETURN ( SELECT * FROM Suppliers WHERE SupplierID = @SupplierID )
I have been testing the performance of the following SQL statements:
Code:
1. SELECT * FROM Products INNER JOIN Suppliers ON (Products.SupplierID = Suppliers.SupplierID) WHERE Products.SupplierID = 3
2. SELECT * FROM dbo.fnProductsRetrieveBySupplierID (3), dbo.fnSuppliersRetrieveBySupplierID (3)
I have built a loop to execute each statement multiple times and then compare the execution times. Although both queries produce the same result, the 2nd one (which uses the functions) is about twice as slow, does anyone know why?
I am joining three tables each table has got about 1.5 million rows,selecting data from these three tables and inserting into a table,to avoid transaction log issues I am running the query in a batch of size 50,000 rows,it is taking about 5hrs to insert all the 1.5 millions rows.
All the columns in the where clause have proper indexes,I ran show plan for the query and it is using indexes properly and not doing any table scan.I updated the statistics for all the indexes also.
query looks some thing like this.
insert into table d (col1,col2,col3,.............. ) values (a.col1,b.col2,c.col3 .....................) from a,b,c where a.id = b.id and a.id = c.id and a.id in between @minid and @currid
The @minid starts from 1 and @currid starts from 50000 ,I am running this in a loop, in next iteration @minid will become 50001 and currid 100,000 and so on.
I have two tables. Employee EmployeeCode int Primary Key
Employee_Stock EmployeeCode int StockCode varchar(10) Primay key on (Employeecode, StockCode)..
There is no foreign key relation between these 2 tables. Now my question is which query give more performance. and why? 1. Select * from Employee INNER JOIN Employee_Stock on Employee.Employeecode = Employee_Stock.EmployeeCode
2. Create a foreign Key between Employee and Employee_Stock for EmployeeCode. and run the same query.
Actually we forgot to put the foreign key relationship between these 2 tables and we have lot of queries joining them.. Now if we add foreignkey, is it going to improve the performance or not?
I wrote a query and I use cursor in the query. When I run the query on dev box it takes 3 mins. I moved the query to EPM database box and it takes forever to run. Usually EPM database query performance is much better. How do I start debugging the poor performance?
How can I check if the query is creating any table locks?
Purpose of query: I get all the Companies (20000) and loop thru each company in the cursor and do calculations.
