Transaction means the actions user perform in a database, like create table, update, select. Is that correct? Can back up or restore be transactions?
I recently read the tool-kit book and encountered 'uncommitted transactions' many times, esp. in the chapter of 'Backup and Recovery'. For example, today I wanna backup my database by backuping a full database, then three hours later performing a differential backup, and five mins later do transaction log backup. Then I restore those backups following the same sequence. When I restore diferential backup and log backup, I have the option to use one of the three options:
Leave the database ready for use by rolling back the uncommitted transactions. Additional transaction logs cannot be restored. (RESTORE WITH RECOVERY)
Leave the database non-operational, and do not roll back the uncommitted transactions. Additional transaction logs can be restored. (RESTORE WITH NORECOVERY)
Leave the database in read-only mode. Undo uncommitted transactions, but save the undo actions in a standby file so that recovery effects can be reverted. (RESTORE WITH STANDBY)
In the definitions above, 'uncommitted transactions' are all mentioned.
I do not understand why uncommitted transaction happned during or before or after backup( in my opinion, all transactions should be committed before you doing backup)? Can you please give me an example?
I haven't used the READ UNCOMMITTED transaction isolation levelbefore, and I was wondering if this would be an appropriate use:I have an ID table containing ID numbers that are randomly generatedand need to be unique. There is a stored procedure that potentiallygenerates thousands of these IDs in one execution and inserts theminto the ID table and various other tables. The basic idea is asfollows:Begin TransactionWhile not all IDs generated {GenID:@NewID = GenerateID()If @NewID exists in ID tableGOTO GenIDInsert into ID tableInsert into various other tables}Commit TransactionThe problem occurs when the stored procedure is being run by more thanone process concurrently. The check to see whether @NewID exists inthe ID table will block, waiting for the transaction in the otherprocess to commit.Would this be an appropriate place to use the READ UNCOMMITTEDisolation level to allow different executions of the stored procedureto see what the others are writing into the ID table before thetransactions finish? I only really care that the IDs generated areunique; they're not in sequence or anything like that. Has anyone hadexperience with anything similar?
1. In this topichttp://groups.google.com/group/comp...b21516252b65e7c,someone wrote: "I've implemented SET TRANSACTION ISOLATION LEVEL READUNCOMMITTED at the beginningof a number of stored procedures and, then SET TRANSACTION ISOLATIONLEVEL READCOMMITTED at the end to minimize the disruption to the application.".My question is, do you really need to set READ COMMITTED at the end ofstored procedure? What scope does that command affect?2. Could someone write some real world example where i should neverread uncommitted data... i'm having trouble understanding when ishould and when i should not use it.
Are there really any benefit on using Read Uncommitted Isolation Level or having a NOLOCK hints for retrieve queries when the default Isolation level just Read Committed (not using COM+). I'm confused why the Community Server uses this technique perhaps for perf issues but I couldn't see any reason why...
We have found an issue with using MSS 2005 with odbc connections, some of our code inserts data, then reselects the data back with a select using a different handle. This hasn't caused any issues before but in one customer this causes a lock up. The timeout error doesn't occur as you would expect if trying to select data that is uncommitted by another user.
Although obviously we could re-code to avoid selecting uncommitted rows, can anyone tell me why this works sometimes but not others. Some kind of setting in MSS that we're unaware of maybe. The code works ok on other MSS 2005 & MSS 2000 servers and oracle & sqlbase.
Hi Sql gurus :))I've got a question that I couldn't find a satisfying answer on the net.What is the difference between:1) running sql query (select from sth with nolock) with no transaction2) running sql query (select from sth) withing a TransactionScope with option Read Uncommitted dataBasically, both should do the same work. However is anyone aware of any potential problems using any of both approaches ?We use 1) to improve our web application scalability since the system works in such a way that any selects and updates on that table (sth) do not interfere with one another.However, updates are done in a TransactionScope. And when having simultaneous select with nolock and update in a Transaction scope (the select statement has a where clause and returns records that are not updated by the update statement). However sometimes ( we still cannot figure it out when) the select statement returns some records twice.For example, the select should return 1000 records , but (sometimes) it returns 1002 records ( the extra 2 records are copies of some of the original 1000 records).Removing the nolock, makes the problem does not appear - but i want to be 100% sure that nolock is our troublemaker. And if it is - why ?We also have a problem that this particular nolock select sometimes return even less records than it should.I know it sounds impossible but it happens.So anyone who has experience with select with nolock, please share :)Thanks in advance, Yani
Yesterday, we have had a sudden load in our SQL Server 2000 which resulted in several locks. There was not too much time to investigate as we had to rush. A team member had reviewed the processes in EM, Manegement, Current Activity. Looking for blocking processes and killed them.
She told me that as soon as the blocking SPID was killed, another one arose and she had to repeat the operation a dozen of time. When done, the server activity was back to normal. She noticed that more than half of the blocking processes showed that they executed the stored Proc "P_SearchProducts".
We don't own the server and the information on what had happened at that time (batches or resource intensive operations, etc.) is not available for now.
The team suggests that we set the Transaction Isolation Level to Read UNCOMMITTED for this SP. I would like to know better about locks before I go ahead.
P_SearchProducts returns 5 recordsets each one could contains from 1 to 200 rows. To achieve the results, it creates about 10 intermediate tables (SELECT ... INTO #TableX) these temp tables are then used progressively to arrive to the final results. Roughly the volume of these temp tables could be double than the final results. The developer who wrote this SP is not a guru in SQL, there is room for improvement. But here are my questions:
Q1. Could the series SELECT ... INTO #TableX in P_SearchProducts prevent or lock another connection from executing the same SP? If yes, under which conditions?
Q2. Let's assume that P_SearchProducts has a slow execution time. Could it prevent another connection from updating the Product table? And thus leading to a deadlock situation? Something like another transaction (by User2) has obtained lock on most of Product tables, except the Product table which were being slowly read by User1 executing P_SearchProducts. But User1 cannot read the other product tables b/c there are locks by User2.
Q3. If the contention issue was provoked by the slow execution time of many request to exec P_SearchProducts (let's assume there were suddenly 50 users on the web hitting the search product feature at the same time). Could the Read Uncommitted magically resolve the contention issue, providing we accept the consequences of the dirty read.
Sorry for the long post and thank you in advance for any help.
I'm getting this when executing the code below. Going from W2K/SQL2k SP4 to XP/SQL2k SP4 over a dial-up link.
If I take away the begin tran and commit it works, but of course, if one statement fails I want a rollback. I'm executing this from a Delphi app, but I get the same from Qry Analyser.
I've tried both with and without the Set XACT . . ., and also tried with Set Implicit_Transactions off.
set XACT_ABORT ON Begin distributed Tran update OPENDATASOURCE('SQLOLEDB','Data Source=10.10.10.171;User ID=*****;Password=****').TRANSFERSTN.TSADMIN.TRANSACTIONMAIN set REPFLAG = 0 where REPFLAG = 1 update TSADMIN.TRANSACTIONMAIN set REPFLAG = 0 where REPFLAG = 1 and DONE = 1 update OPENDATASOURCE('SQLOLEDB','Data Source=10.10.10.171;User ID=*****;Password=****').TRANSFERSTN.TSADMIN.WBENTRY set REPFLAG = 0 where REPFLAG = 1 update TSADMIN.WBENTRY set REPFLAG = 0 where REPFLAG = 1 update OPENDATASOURCE('SQLOLEDB','Data Source=10.10.10.171;User ID=*****;Password=****').TRANSFERSTN.TSADMIN.FIXED set REPFLAG = 0 where REPFLAG = 1 update TSADMIN.FIXED set REPFLAG = 0 where REPFLAG = 1 update OPENDATASOURCE('SQLOLEDB','Data Source=10.10.10.171;User ID=*****;Password=****').TRANSFERSTN.TSADMIN.ALTCHARGE set REPFLAG = 0 where REPFLAG = 1 update TSADMIN.ALTCHARGE set REPFLAG = 0 where REPFLAG = 1 update OPENDATASOURCE('SQLOLEDB','Data Source=10.10.10.171;User ID=*****;Password=****').TRANSFERSTN.TSADMIN.TSAUDIT set REPFLAG = 0 where REPFLAG = 1 update TSADMIN.TSAUDIT set REPFLAG = 0 where REPFLAG = 1 COMMIT TRAN
It's got me stumped, so any ideas gratefully received.Thx
I have a design a SSIS Package for ETL Process. In my package i have to read the data from the tables and then insert into the another table of same structure.
for reading the data i have write the Dynamic TSQL based on some condition and based on that it is using 25 different function to populate the data into different 25 column. Tsql returning correct data and is working fine in Enterprise manager. But in my SSIS package it show me time out ERROR.
I have increase and decrease the time to catch the error but it is still there i have tried to set 0 for commandout Properties.
if i'm using the 0 for commandtime out then i'm getting the Distributed transaction completed. Either enlist this session in a new transaction or the NULL transaction.
and
Failed to open a fastload rowset for "[dbo].[P@@#$%$%%%]". Check that the object exists in the database.
Is it possible to set READ UNCOMMITTED to a user connecting to an SQL2000 server instance? I understand this can be done via a front endapplication. But what I am looking to do is to assign this to aspecific user when they login to the server via any entry application.Can this be set with a trigger?
I am getting this error :Distributed transaction completed. Either enlist this session in a new transaction or the NULL transaction. Description: An unhandled exception occurred during the execution of the current web request. Please review the stack trace for more information about the error and where it originated in the code. Exception Details: System.Data.OleDb.OleDbException: Distributed transaction completed. Either enlist this session in a new transaction or the NULL transaction.have anybody idea?!
i have a sequence container in my my sequence container i have a script task for drop the existing tables. This seq. container connected to another seq. container. all these are in for each loop container when i run the package it's work fine for 1st looop but it gives me error for second execution.
Message is like this:
Distributed transaction completed. Either enlist this session in a new transaction or the NULL transaction.
i am getting this error "Distributed transaction completed. Either enlist this session in a new transaction or the NULL transaction.".
my transations have been done using LINKED SERVER. when i manually call the store procedure from Server 1 it works but when i call it through Service broker it dosen't work and gives me this error.
I have Full database backup upto previous day and transaction logfile of Today transaction. my database has crashed. I have restored previous day's Full backup. I have faced difficulty to restore today's transaction from today's transaction log. What are the steps to restore full database back and one day's transaction log file. Note: there is no differential database backup and transaction backup.
I'm receiving the below error when trying to implement Execute SQL Task.
"The ROLLBACK TRANSACTION request has no corresponding BEGIN TRANSACTION." This error also happens on COMMIT as well and there is a preceding Execute SQL Task with BEGIN TRANSACTION tranname WITH MARK 'tran'
I know I can change the transaction option property from "supported" to "required" however I want to mark the transaction. I was copying the way Import/Export Wizard does it however I'm unable to figure out why it works and why mine doesn't work.
I created a Calculated measure in cube something like this : ([TransType].[TransTypeHierarchy].[TransTypeCategoryParent].&[SPEND],[Measures].[Transaction Amount]). To get only spend transactions. Now, I want to slice this measure with same hierarchy to find the amount distribution across different transaction types under spend transaction. But this query behaving like the measure doesn't have relation with measure.
you can think this as below query: WITH MEMBER SPEND AS ([TransType].[TransTypeHierarchy].[TransTypeCategoryParent].&[SPEND],[Measures].[Transaction Amount]) SELECT NON EMPTY {SPEND} ON 0 ,NON EMPTY ([TransType].[TransTypeHierarchy].[TransTypeCategoryParent]) ON 1 FROM [CUBE]
How do I make use of begin transaction and commit transaction in SSIS.
As am not able to commit changes due to certain update commands I want to explicitly write begin and commit statements. but when i make use of begin and commit in OLEDB commnad stage it throws an error as follows:
Hresult:0x80004005
descriptionyntax error or access violation.
its definately not an syntax error as i executed it in sql server. also when i use it in execute sql task out side the dataflow container it doesnt throw any error but still this task doesnt serve my purpose of saving/ commiting update chanages in the database.
I am having some problem with SSIS transaction. Eventhought I tried to imitate the concept that Jamie presented at http://www.sqlservercentral.com/columnists/jthomson/transactionsinsqlserver2005integrationservices.asp
. My workflow is as followed
********************************* For Each ADO.Record in Oracle (transaction=not supported)
If (Certain_Field_Value = 'A')
Lookup Data in SQL DB with values from Oracle (transaction=not supported)
DO Sequence A (Start a Transaction , transaction=required)
INSERT/UPDATE some records in SQLDB(transaction=supported) Finish Sequence A ( transaction should stop here) UPDATE Oracle DB ( Execute SQLTask, transaction=not supported) If (Certain_Field_Value = 'B')
Lookup Data in SQL DB with values from Oracle (transaction=not supported)
DO Sequence B (Start a Transaction , transaction = required)
INSERT/UPDATE some records in SQLDB (transaction=supported) Finish Sequence A ( transaction should stop here) UPDATE Oracle DB ( Execute SQLTask, transaction=not supported) If (Certain_Field_Value = 'C')
------------ ------------ End ForEach Loop ************************************* My requirements are that I want separate transaction for each Sequence A, B, C, etc... If Sequence A transaction fails, the other should still be continuing with another transaction. But I am getting an error regarding the OLEDB Error in next Task (e.g in Certain_Field_Value = 'B') "Lookup Data in SQL DB with values from Oracle ", the error message is ".......Distributed transaction completed. Either enlist this session in a new transaction or the NULL transaction. ". What is it that I am doing wrong? Regards KyawAM
The operation could not be performed because the OLE DB provider 'SQLOLEDB' was unable to begin a distributed transaction. [OLE/DB provider returned message: New transaction cannot enlist in the specified transaction coordinator. ] OLE DB error trace [OLE/DB Provider 'SQLOLEDB' ITransactionJoin::JoinTransaction returned 0x8004d00a].
http://support.microsoft.com/kb/839279 this didn't help
I am executing a stored procedure something like this
Create Procedure TEST @test1 @test2 AS BeGIN TRANSACTION ONE SELECT... UPDATE.. .... ....
.... TRUNCATE etc and lot of Select,update and delete statements like this ..... COMMIT TRANSACTION ONE
The Block of code which I have b/w BEGIN TRANSACTION AND COMMIT TRANSACTION ..Will it be rolled back if it encounters any errors in the SELECT,UPPDATE,DELETE ..statements which I have with the transaction one. IF not How do I roll back if it encounters any erros b/w the BEGIN TRANSACTION and END TRANSACTION.
---------------------------------------------- dim conn, connectionstring
connectionstring= "Provider=SQLOLEDB.1; Data Source = blahblah; Initial Catalog = abc; User Id = osss; Password=xxx"
set conn = server.CreateObject("adodb.connection") conn.open connectionstring
----------------------------------------------
It's just basically to set up the connection to the SQL server, it works on my other pages, but on a few pages, the last line (conn.open connectionstring) triggers this error:
"Microsoft OLE DB Provider for SQL Server error '8004d00a'
New transaction cannot enlist in the specified transaction coordinator. "
I've never encountered this error before and I couldn't think of any solution... please help!!!
I had thought that if any statement failed within a BEING TRANS .. COMMIT TRANS block, then all the statements would be rolled back. But I am seeing different behavior (SQL Server 2000 8.00.2039)
For instance, run these statements to set up a test: --DROP TABLE testTable1 --DROP TABLE testTable2 CREATE TABLE testTable1 (f1 varchar(1)) CREATE TABLE testTable2 (f1 varchar(1)) CREATE UNIQUE INDEX idx_tmptmp ON testTable1 (f1) insert into testTable1(f1) values ('a')
So table testTable1 has a unique index on it..
Now try to run these statements:
--DELETE FROM testTable2 BEGIN TRANSACTION insert into testTable1(f1) values ('a') insert into testTable2(f1) values ('a') COMMIT TRANSACTION
SELECT * FROM testTable2
..the first insert fails on the unique index.. but the second insert succeeds. Shouldn't the second insert roll back? How can I make two operations atomic?
Hi,On My local SQL server I have added a linked server to another SQLserver (remoteserver) in another Windows NT Domain.When I run this codeselect count(*) from remoteserver.mosaics.dbo.LocationThis works fine.However when I usebegin transactionselect count(*) from remoteserver.mosaics.dbo.LocationIt errors out saying thatThe operation could not be performed because the OLE DB provider'SQLOLEDB' was unable to begin a distributed transaction.New transaction cannot enlist in the specified transactioncoordinator. ]OLE DB error trace [OLE/DB Provider 'SQLOLEDB'ITransactionJoin::JoinTransaction returned 0x8004d00a].My question is even though I am just reading data from theremoteserver, why does the local transaction get promoted to adistributed transaction.Any help will be grately appreciated.TIA...Rohit
I am trying transfer data from Back Office Server to Head Office using DTS. It is failing in few stores, rest of the store it is OK
Configuration
Head office :Windows 2003 SP1 and Sql Server 2000 SP3
Failing Store:Windows 2003 SP2 and SQL SERVER 2005
Successful Store :Windows 2003 SP2 qnd SQL SERVER 2000
At Store: Setting for MSDTC
Log on Account for MSDTC Service : Network Service
Network DTC Access = True
Allow Inbound = True
Allow Outbound = True
No Authentication Required = True
TurnOffRPCSecurity = 1
port Ranges for RPC = 5000- 5100
The error Message is as follows:
(Microsoft Data Transformation Services (DTS) Package (8004d00a): Connection 'Head Office SQL Server' for Task 'DTSTask_DTSDataPumpTask_1' does not support joining distributed transactions or failed when attempting to join. Unable to enlist in the transaction. ) (Microsoft OLE DB Provider for SQL Server (8004d00a): New transaction cannot enlist in the specified transaction coordinator. )
If any one can help me, that will be great!!! Thanks in advance
With the function below, I receive this error:Error:Transaction count after EXECUTE indicates that a COMMIT or ROLLBACK TRANSACTION statement is missing. Previous count = 1, current count = 0.Function:Public Shared Function DeleteMesssages(ByVal UserID As String, ByVal MessageIDs As List(Of String)) As Boolean Dim bSuccess As Boolean Dim MyConnection As SqlConnection = GetConnection() Dim cmd As New SqlCommand("", MyConnection) Dim i As Integer Dim fBeginTransCalled As Boolean = False 'messagetype 1 =internal messages Try ' ' Start transaction ' MyConnection.Open() cmd.CommandText = "BEGIN TRANSACTION" cmd.ExecuteNonQuery() fBeginTransCalled = True Dim obj As Object For i = 0 To MessageIDs.Count - 1 bSuccess = False 'delete userid-message reference cmd.CommandText = "DELETE FROM tblUsersAndMessages WHERE MessageID=@MessageID AND UserID=@UserID" cmd.Parameters.Add(New SqlParameter("@UserID", UserID)) cmd.Parameters.Add(New SqlParameter("@MessageID", MessageIDs(i).ToString)) cmd.ExecuteNonQuery() 'then delete the message itself if no other user has a reference cmd.CommandText = "SELECT COUNT(*) FROM tblUsersAndMessages WHERE MessageID=@MessageID1" cmd.Parameters.Add(New SqlParameter("@MessageID1", MessageIDs(i).ToString)) obj = cmd.ExecuteScalar If ((Not (obj) Is Nothing) _ AndAlso ((TypeOf (obj) Is Integer) _ AndAlso (CType(obj, Integer) > 0))) Then 'more references exist so do not delete message Else 'this is the only reference to the message so delete it permanently cmd.CommandText = "DELETE FROM tblMessages WHERE MessageID=@MessageID2" cmd.Parameters.Add(New SqlParameter("@MessageID2", MessageIDs(i).ToString)) cmd.ExecuteNonQuery() End If Next i ' ' End transaction ' cmd.CommandText = "COMMIT TRANSACTION" cmd.ExecuteNonQuery() bSuccess = True fBeginTransCalled = False Catch ex As Exception 'LOG ERROR GlobalFunctions.ReportError("MessageDAL:DeleteMessages", ex.Message) Finally If fBeginTransCalled Then Try cmd = New SqlCommand("ROLLBACK TRANSACTION", MyConnection) cmd.ExecuteNonQuery() Catch e As System.Exception End Try End If MyConnection.Close() End Try Return bSuccess End Function
Hello, I've a problem with a software developed in C# with the framework 2.0. This is the error I receive : The operation could not be performed because OLE DB provider "SQLNCLI" for linked server "XXX_LINKED_SERVER" was unable to begin a distributed transaction. OLE DB provider "SQLNCLI" for linked server "XXX_LINKED_SERVER" returned message "No transaction is active.". If I try directly to restart the process, it works fine. Is there someone who can help me ? This is the process 1. In C# --> Call of a Query : select from the linked server (db in sql 2005) and insert into a table SQL 2005 2. In the C# --> using (TransactionScope scope = new TransactionScope()) and insert in a table in SQL 2005 which is link server Thank in advance.
I found the following link which seems to be the problem we're experiencinghttp://support.microsoft.com/kb/937517
The link includes a workaround which is the following: "To prevent the SQLNCLI provider from sending an attention signal to the server, use the SQLNCLI provider to consume fully any rowsets that the OLE DB consumer creates. "
How do I use the SQLNCLI provider to fully consume any rowsets?
Hello everyone,This is more of an architectural question about SQL Server. Cansomeone please explain why when I perform a query such as the onebelow that updates a table using begin and end transaction I am unableto programmatically truncate the transaction log. The only way I havefound to truncate the transaction log is to stop and start the SQLServer Service. Does this transaction use the tempdb? Is that why Iam unable to truncate the transaction log? Is there a better way todo this?Begin trans T1Update sometableSet random_row = 'blah'End trans T1Thanks!
I have a large database in full recovery model (9.0.3152).
I have s stored procedure, that generates a HUGE transaction log, i have optimized the stored proc as much as i can, i have also broken it up into smaller transactions that i commit more frequently and do transaction log backups more frequently.
However i cannot make a significant dent into the transaction log size.
Is there anyway / syntax to ensure that a transaction or statement is not logged to the transaction log ?
I will never want to have this transaction or commands present if i do a restore.
