Is It Possible To Read Data From A Table With Exclusive Lock ?
Sep 4, 2006
Hello,
We currently use SQL Serv 2000 with an ERP application and VB applications.
Both system work with the same database & tables but the ERP application seems to put exclusive lock on all tables it needs during processes. So our VB applications are not able to read these data and we receive TIMEOUT error.
Hello All! I want to perform 4 or 5 statements as a transaction but I need to make sure that during this complete transaction no one else inserts or deletes records from a table named SomeTable. So how can I lock MyTable at the beggining of the transaction so that during my transaction no one else can insert or delete anything in table SomeTable? Thanks! David
Anybody know how a SELECT statement can generate an exclusive lock on a table ? I always thought that SELECT's take out shared locks. Is this something to do with temporary tables generated by ORDER BY's and DISTINCT ? Rogue SQL below (from Site Server).
SELECT A.i_Dsid, A.i_Aid, A.vc_Val, A.i_Val, A.dt_Val, A.img_Val FROM Object_Attributes A, ( SELECT DISTINCT L.i_Dsid FROM Object_Lookup L , Object_Attributes OA2 (index = IND_vc_Aid) WHERE ((( L.i_ObjectClass = 9999 )) AND ( OA2.vc_Val LIKE ( '999999999.9999999%' ) AND OA2.i_Aid = 99)) AND (L.i_Container_Dsid = 99) AND ( OA2.i_Dsid = L.i_Dsid )) AS B WHERE B.i_Dsid = A.i_Dsid AND A.i_Aid NOT IN( 1, 2, 3, 4, 5 ) ORDER BY A.i_Dsid, A.i_Aid
Is it possible to place an exclusive row lock when running a SELECT query by using a lock hint (or otherwise).
Basically, when a select statement is run against a table I don't won't any other users to read that row until it has been updated - at some later stage.
Any suggestions on whether this is possible would be welcome.
I'm relatively new to SQL and I've come across something that doesn't seem quite right. When an insert becomes part of an transaction I notice an exclusive KEY lock in Enterprise Manager. The table in question was using a Clustered index but I changed that, dropped the table and brought it back in but I still get the lock which keeps all others out of the table. Is this the expected behavior or is there something I am missing? Could the size of the tabe affect things? This is a very small table currently. I'm using MSSQL 7 sp3.
Hi , I have some issues with deadlock.I am getting deadlock becuase of two select on same table. The sql server log is like this , Select statements should have always shared lock.I am not getting why its doing exclusive lock and creating deadlock.
5/6/2008 12:38 spid4s Unknown Deadlock encountered €¦. Printing deadlock information 5/6/2008 12:38 spid4s Unknown Wait-for graph 5/6/2008 12:38 spid4s Unknown Log Viewer could not read information for this log entry. Cause: Data is Null. This method or property cannot be called on Null values.. Content: 5/6/2008 12:38 spid4s Unknown Node:1 5/6/2008 12:38 spid4s Unknown KEY: 9:72057594050117632 (8d036f07c58f) CleanCnt:3 Mode Flags: 0Ă—0 5/6/2008 12:38 spid4s Unknown Grant List 3: 5/6/2008 12:38 spid4s Unknown Owner:0Ă—12E9F160 Mode: S Flg:0Ă—0 Ref:1 Life:00000001 SPID:68 ECID:0 XactLockInfo: 0Ă—353D1C54 5/6/2008 12:38 spid4s Unknown SPID: 68 ECID: 0 Statement Type: SELECT Line #: 4 5/6/2008 12:38 spid4s Unknown Input Buf: Language Event: (@actDefId nvarchar(36)@stateList varchar(1)@stateList1 varchar(1)@procRelObjType smallint@procRelObjIdList varchar(36)) 5/6/2008 12:38 spid4s Unknown Requested By: 5/6/2008 12:38 spid4s Unknown ResType:LockOwner Stype:€™OR€™Xdes: 0Ă—2FBB67F0 Mode: X SPID:112 BatchID:0 ECID:0 TaskProxy0Ă—0792E378) Value:0Ă—38baa20 Cost0/11888) 5/6/2008 12:38 spid4s Unknown Log Viewer could not read information for this log entry. Cause: Data is Null. This method or property cannot be called on Null values.. Content: 5/6/2008 12:38 spid4s Unknown Node:2 5/6/2008 12:38 spid4s Unknown KEY: 9:72057594049986560 (6f02e1cd37c3) CleanCnt:3 Mode:X Flags: 0Ă—0 5/6/2008 12:38 spid4s Unknown Wait List: 5/6/2008 12:38 spid4s Unknown Owner:0Ă—12396EE0 Mode: S Flg:0Ă—2 Ref:1 Life:00000000 SPID:90 ECID:0 XactLockInfo: 0Ă—0AA8178C 5/6/2008 12:38 spid4s Unknown SPID: 90 ECID: 0 Statement Type: SELECT Line #: 4 5/6/2008 12:38 spid4s Unknown Input Buf: Language Event: (@actDefId nvarchar(36)@stateList varchar(1)@stateList1 varchar(1)@procRelObjType smallint@procRelObjIdList varchar(36)) 5/6/2008 12:38 spid4s Unknown Requested By: 5/6/2008 12:38 spid4s Unknown ResType:LockOwner Stype:€™OR€™Xdes: 0Ă—353D1C30 Mode: S SPID:68 BatchID:0 ECID:0 TaskProxy0Ă—13B3E378) Value:0Ă—12e9e780 Cost0/6164) 5/6/2008 12:38 spid4s Unknown Log Viewer could not read information for this log entry. Cause: Data is Null. This method or property cannot be called on Null values.. Content:
If you have any idea regarding this please let me know ASAP.
Error: The Script returned a failure result. Task SCR REIL Data failed
OnError - Task SQL Insert Error Msg Error: A deadlock was detected while trying to lock variable "System::ErrorCode, System::ErrorDescription, System::ExecutionInstanceGUID, System::StartTime, User::FEED_ID, User::t_ProcessedFiles" for read access. A lock could not be acquired after 16 attempts and timed out. Error: The expression ""EXEC [dbo].[us_sp_Insert_STG_FEED_EVENT_LOG] @FEED_ID= " + (DT_WSTR,10) @[User::FEED_ID] + ", @FEED_EVENT_LOG_TYPE_ID = 3, @STARTED_ON = '"+(DT_WSTR,30)@[System::StartTime] +"', @ENDED_ON = NULL, @message = 'Package failed. ErrorCode: "+(DT_WSTR,10)@[System::ErrorCode]+" ErrorMsg: "+@[System::ErrorDescription]+"', @FILES_PROCESSED = '" + @[User::t_ProcessedFiles] + "', @PKG_EXECUTION_ID = '" + @[System::ExecutionInstanceGUID] + "'"" on property "SqlStatementSource" cannot be evaluated. Modify the expression to be valid.
Warning: The Execution method succeeded, but the number of errors raised (4) reached the maximum allowed (1); resulting in failure. This occurs when the number of errors reaches the number specified in MaximumErrorCount. Change the MaximumErrorCount or fix the errors.
And how did I get 4 errors? - I only set my script task result to failure
I have a requirement to read a value from table and increment it by 1. There can be multi-threads doing the same operation and would need a ROW LOCK so that read and write both are atomic. How can i put an exclusive lock on the row before I read the value from the table.
CREATE TABLE [dbo].[tblOnboardingSequence]( [OnboardingSequenceID] [uniqueidentifier] NOT NULL, [Name] [nvarchar](255) NOT NULL, [NextNumber] [bigint] NOT NULL, CONSTRAINT [PK_OnboardingSequence] PRIMARY KEY CLUSTERED( [OnboardingSequenceID] ASC )WITH (PAD_INDEX = OFF, STATISTICS_NORECOMPUTE = OFF, IGNORE_DUP_KEY = OFF, ALLOW_ROW_LOCKS = ON, ALLOW_PAGE_LOCKS = ON) ON [PRIMARY] ) ON [PRIMARY]
GO
My Stored Procedure has below logic
DECLARE @NextNumber BIGINT ----------- Acquire row lock here SELECT @NextNumber = NextNumber FROM tblOnboardingSequence WHERE Name = 'TPO' UPDATE tblOnboardingSequence SET NextNumber = @NextNumber + 1 WHERE Name = 'TPO' ----------- Release row lock here
I would like to have a row lock for the row having Name "TPO" before SELECT query and release after UPDATE query. What si the best way to deal with this?
Hi, I have set of 2 DTS packages, one of which calls the other by forming a command-line (dtexec) using a Execute Process task.
From the parent package-> Execute Process Task-> dtsexec /F etc... /<pkg variable> = "servername"
Each of the parent and the called package have a variable: "User::DWServerSQLInstance" which is mapped to the SQL server connection manager server name property using an expression. The outer package has the above variable and so does the inner called package (which gets assigned through the command line from the outerpackage call to inner)
I "sometimes" get the following error:
OnError,I4,TESTDOMAdministrator,ACDWAggregation,{A1F8E43F-15F1-4685-8C18-6866AB31E62B},{77B2F3C7-6756-46EB-8C01-D880598FB4B3},5/22/2006 5:10:28 PM,5/22/2006 5:10:28 PM,-1073659822,0x,The variable "User::DWServerSQLInstance" is already on the read list. A variable may only be added once to either the read lock list or the write lock list.
Help would be appreciated!
I have seen other posts on this but, not able to relate the solution to my scenario.
Package works fine when run from BIDS, DTExec, dtexecui. When I schedule it, It get these random errors. (See below)
The main culprit is a variable called "RecordsetFileDIR" which is set using an expression. (@[User::_ROOT] + "RecordSets\")
A number of other variables use this as part of their expression and as they all fail, pretty much everything dies.
I have installed SP1 (Not Beta) on server. Package uses config files to set the value of _ROOT.
The error does not always seem to be with this particular variable though. Always a variable that uses an expression but errors are random. Also, It will run 3 out of 10 times without a problem. I am the only person on the server at the time.
Any ideas?
Cheers,
Crispin
Error log:
OnError,,,POSBasketImport,,,10/05/2006 12:03:34,10/05/2006 12:03:34,-1073659822,0x,The variable "User::RecordsetFileDIR" is already on the read list. A variable may only be added once to either the read lock list or the write lock list.
OnError,,,POSBasketImport,,,10/05/2006 12:03:34,10/05/2006 12:03:34,-1073639420,0x,The expression for variable "rsHeaderFile" failed evaluation. There was an error in the expression.
OnError,,,DF_Header_Header,,,10/05/2006 12:03:34,10/05/2006 12:03:34,-1071636247,0x,Accessing variable "User::rsHeaderFile" failed with error code 0xC00470EA.
OnError,,,Move All Data,,,10/05/2006 12:03:34,10/05/2006 12:03:34,-1071636247,0x,Accessing variable "User::rsHeaderFile" failed with error code 0xC00470EA.
OnError,,,Load Open Batches and Process Files,,,10/05/2006 12:03:34,10/05/2006 12:03:34,-1071636247,0x,Accessing variable "User::rsHeaderFile" failed with error code 0xC00470EA.
OnError,,,POSBasketImport,,,10/05/2006 12:03:34,10/05/2006 12:03:34,-1071636247,0x,Accessing variable "User::rsHeaderFile" failed with error code 0xC00470EA.
OnError,,,DF_Header_Header,,,10/05/2006 12:03:34,10/05/2006 12:03:34,-1071636390,0x,The file name is not properly specified. Supply the path and name to the raw file either directly in the FileName property or by specifying a variable in the FileNameVariable property.
OnError,,,Move All Data,,,10/05/2006 12:03:34,10/05/2006 12:03:34,-1071636390,0x,The file name is not properly specified. Supply the path and name to the raw file either directly in the FileName property or by specifying a variable in the FileNameVariable property.
OnError,,,Load Open Batches and Process Files,,,10/05/2006 12:03:34,10/05/2006 12:03:34,-1071636390,0x,The file name is not properly specified. Supply the path and name to the raw file either directly in the FileName property or by specifying a variable in the FileNameVariable property.
OnError,,,POSBasketImport,,,10/05/2006 12:03:34,10/05/2006 12:03:34,-1071636390,0x,The file name is not properly specified. Supply the path and name to the raw file either directly in the FileName property or by specifying a variable in the FileNameVariable property.
OnError,,,DF_Header_Header,,,10/05/2006 12:03:34,10/05/2006 12:03:34,-1073450901,0x,"component "rsHeader" (365)" failed validation and returned validation status "VS_ISBROKEN".
OnError,,,Move All Data,,,10/05/2006 12:03:34,10/05/2006 12:03:34,-1073450901,0x,"component "rsHeader" (365)" failed validation and returned validation status "VS_ISBROKEN".
OnError,,,Load Open Batches and Process Files,,,10/05/2006 12:03:34,10/05/2006 12:03:34,-1073450901,0x,"component "rsHeader" (365)" failed validation and returned validation status "VS_ISBROKEN".
OnError,,,POSBasketImport,,,10/05/2006 12:03:34,10/05/2006 12:03:34,-1073450901,0x,"component "rsHeader" (365)" failed validation and returned validation status "VS_ISBROKEN".
Hi,Version Info: SQLSERVER 2000 SP3I am trying to understand how SQL Server works with SERIALIZABLE read.I am fairly new to SQL Server, having mainly worked with Informix.We are getting lock timeout error in our application. Our lock timeoutis set to 20 seconds. I am trying to investigate why locks are held forsuch a long time in the first place.I believe SQLServer tries to put keylocks as much as possible forensuring serializibility. For e.g.SELECT column_bfrom table_awhere column_c between 1000 and 1100what if column_c has no index. Does it switch over the data row.And what if a table has no index. Will it go for table lock, as ituse to do in earlier versions.TIA.--email id is bogus
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INPUT: A table contains 2 columns with data i need. column A=Filename and column B=FileContent
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I want to lock a table so others cannot lock it but able to read it inside transactions.
The coding I need is something like this: set implicit_transactions on begin transaction select * from table1 with (tablock, holdlock) update table2 set field1 = 'test' commit transaction commit transaction
I have tried the coding above, it won't prevent others from locking table1.
So, I changed the tablock to tablockx to prevent others from locking table1. But this will also prevent others from reading table1. So, how can I lock table1 so others cannot lock it but still able to read it?
I have a scenarios where if I execute select * from tbl it should display the all the records without waiting to release any lock. For example suppose I have one table called tbl and one session is updating one records and not committed yet and in other session if i execute select * from table I can see all the records, for that records it can show me older version. but my select statement should not wait to commit another session and also it should not show the modified data.
Hi,all: This problem almost drives me crazy, hope I can get some hints from you guyz!!! Ok, here is the situation: I wanna only one users 2 modify the data(update) from my page each time, and if at the same time, there are some other users connecting my database through .aspx page, they can only browse the data until the first users finish updating. It seems I need to implement locking the database, but I am not sure how I am gonna do that using asp.net!!! Thanx in advance!
hi, i have an application that updates some records in sql tables, and i want to do a web application that updates records in the some database-table(sql) so, my question is how can i lock the row or table so i dont have concurrency problems.tnx in advance.
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Which lock type or isolation level should I use to be sure that no onewill read or write or do anything with the table I'm using?Code block should look something like this:lock tableread value from tablechange value to new_valueupdate table set value = new_valuerelease lockWhile I'm changing the value absolutly no one should be able to readfrom the table.
How can I see which table is locked up by some particular process? I know that I can view paricular spid from 'current activity'. But is there any way I can see which table is the center of problem? I really appreciate your help..
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cmdTemp.CommandText="Select max(certificateNumber) from product_table where certificateNumber<> 8888888" set cert_info=Server.CreateObject("ADODB.RecordSet") cert_info.Open cmdTemp, , AdOpenKeySet, adLockOptimistic If Not cert_info.EOF then