Hi,
I currently have a requirement for access to a SQL Server 2000 box using Access 2003. The queries will sometimes be quite demanding which in turn might affect the rest of the SQL users on the system.
Does anyone know of any setting in Access so that I can achieve the same result as setting the TRANSACTION ISOLATION level using T-SQL?
Any ideas would be much appreciated.
Regards,
Paul.
What is the default transaction isolation level for SQL Server?
and Advantages of having multiple filegroups ?
Is there a way to read data from a linked server,within a transaction, without using DTC?The data on the linked server is static, thereforethere is no need for two-phase commit. There isno need for locking data on the linked server, becauseit is not being updated (either from the remote server,or from the local server).I don't want to run DTC because:1.) there have been security-related flaws with DTC inthe past2.) the application doesn't do distributed updates, andbecause the data on on the remote server is static,there is really no data integrity exposure withoutDTC.I cannot specify "WITH (NOLOCK)" on the select fromthe linked server:Server: Msg 7377, Level 16, State 1, Line 6Cannot specify an index or locking hint for a remote data source.I tried setting the isolation level:SET TRANSACTION ISOLATION LEVEL READ UNCOMMITTEDbut that seems to have no effect on the requirement to use DTC.I still get the message:MSDTC on server 'LOCALSERVER' is unavailable.Is there some other way around this? Is it possible to provide someconnection string parameter, in the linked server setup, that wouldspecify the "READ UNCOMMITTED" isolation level for the linked server,so that DTC wouldn't be necessary.(In other words, can I tell SQL Server, "trust me, this won't hurt"?)Environment: SQL Server 2000 sp4The SQL does something like:declare @x char(4), @k int, @rc1 int, @rc2 intset @k=123BEGIN TRANselect @x=xfrom remoteserver.remotedatabase.dbo.tablewhere k=@kupdate localdatabase.dbo.table1set x=@xwhere k=@kset @rc1=@@errorupdate localdatabase.dbo.table2set x=@xwhere k=@kset @rc2=@@errorif (@rc1 = 0 AND @rc2=0) COMMIT TRANelse ROLLBACK TRAN
View 2 Replies View RelatedI'm investigating a poorly performing procedure that I have never seen before. The procedure sets the transaction isolation level, and I suspect it might be doing so incorrectly, but I can't be sure. I'm pasting a bastardized version of the proc below, with all the names changed and the SQL mucked up enough to get through the corporate web filters.
The transaction isolation level is set, but there is no explicit transaction. Am I right that there are two implicit transactions in this procedure and each of them uses snapshot isolation?
SET NOCOUNT ON;
SET TRANSACTION ISOLATION LEVEL SNAPSHOT;
DECLARE @l_some_type varchar(20),
@some_type_code varchar(3),
@error int,
@error_msg varchar(50);
[Code] .....
Hi all. I have a question. I 've read already about isolation lavels, but I don't understand how in practic set proper isolation if I have say 100 transactions..what is the algoriphm?
View 4 Replies View RelatedHello all,
What is the TRANSACTION ISOLATION LEVEL settings for MSSQL like the default setting in Oracle. In Oracle the default setting allows one session to read consistent data without waiting for the other sessions to commit/rollback the data.
For eg: In Mssql, if I update table A in the first session, and in another session (second session) if I select from table A, the second session waits till the first session completes the updates and commit or rollbacks.
But in Oracle , if I update table A in the first session, and in another session (second session) if I select from table A, the second session will perform a read from the ROLLBACK SEGS and give a read consistent data without waiting for the first session to commit or rollback the transaction.
Is this type of behaviour is possible is MSSQL. And If YES how can I do it?
Thanks for any help
Suresh
Not sure if this is more a .Net question or SQL Server, but I think it belongs here.
I have a small .Net app that reads records from a bunch of files from disk and inserts them into a database table. There could be several hundred files resulting in 100,000 records or more each time its run. Since it's a large table there are of course a few indexes on it so the insert takes a while. For larger sessions it could run as long as an hour. I need it to run in a transaction so that if anything happens while it's running the records from that run were committed on an all or nothing basis. However, I don't want to lock the table at all while the insert is happening. These aren't transaction records or anything like that, and the batches are separated by client so there will be no conflicts (no need to lock the table).
Unfortunately, no matter what I use for the isolation level of the transaction the table always ends up locked for reads. Data from previous runs is live at this point and we can't allow that. I have the choice of the following isolation levels when I create the transaction, but none seems to work:
Chaos
ReadCommitted
ReadUncommitted
RepeatableRead
Serializable
Snapshot
Unspecified
I would expect Chaos, ReadUncommitted, or Snapshot be okay here, but I can't seem to get it working. Any thoughts?
I am redesigning an application that distributes heldesk tickets to our50 engineers automatically. When the engineer logs into their window astored procedure executes that searches through all open tickets andassigns a predetermined amount of the open tickets to that engineer.Theproblem I am running into is that if 2 or more engineers log in at thesame time the stored procedure will distribute the same set of ticketsmultiple times.Originally this was fixed by "reworking" the way SQL Server handlestransactions. The original developer wrote his code like this:-----DECLARE @RET_STAT INTSELECT 'X' INTO #TEMPBEGIN TRANUPDATE #TEMP SET 'X' = 'Y'SELECT TOP 1 @TICKET_# =TICKET_NUMBER FROM TICKETS WHERE STATUS = 'O'EXEC @RET_STAT = USP_MOVE2QUEUE @TICKET_#, @USERIDIF @RET_STAT <> 0ROLLBACK TRANRETURN @RET_STATENDCOMMIT TRAN-----The UPDATE of the #TEMP table forces the transaction to kick off andlocks the row in table TICKETS until the entire transaction hascompleted.I would like to get rid of the #TEMP table and start using isolationlevels, but I am unsure which isolation level would continue to lockthe selected data and not allow anyone else access. Do I need acombination of isolation level and "WITH (ROWLOCK)"?Additionally, the TICKETS table is used throughout the application andI cannot exclusively lock the entire table just for the distributionprocess. It is VERY high I/O!Thanks for the help.
View 3 Replies View RelatedHi,I have 1 SQL statement selecting data from various tables and updating othertables.The question then is how do I prevent other applications from modifying thetables that I'm working on (that is while my transaction is being executed)?I know that the isolation level should be either REPEATABLE READ orSERIALIZABLE. But I need confirmation on if one of these actually solve myissue - prevents other applications/threads from modifying/inserting datainto the same tables that I'm working on.Thanks in advance,Daniel
View 5 Replies View RelatedWhat are the different kinds of Transaction Isolation Level? How they useful in day to day activity as SQL Developer ?
View 2 Replies View RelatedBy setting the TRANSACTION ISOLATION LEVEL READ UNCOMMITTED; is this automatically sets all the joined tables to NOLOCK?
Or, in order this statement to work right, this needs to be only done inside BEGIN TRAN > COMMIT (ROLLBACK) statement?
I need to set the Isolation Level (in ADO) for the Non-transaction queries to SNAPSHOT.
Both the ADO.Connection.IsolationLevel Property and the SQL Server SET TRANSACTION ISOLATION LEVEL command set the Isolation Level for the Transaction queries but no for the non-transaction queries.
I cannot use the READ_COMMITTED_SNAPSHOT database option, becaus when I am in a transaction I need the READ COMMITTED Isolation Level not the SNAPSHOT Isolation Level.
I don't want to rewrite the entire code of my existing application to add (NOLOCK).
Thanks,
Have the need for going to a table to get an identity value. This is for updating an existing database, blah blah blah. Here is the schema of the table we are using:CREATE TABLE [TableIdentityValue] ( [TableName] [varchar] (50) , [NextNegativeIdentity] [int] NOT NULL , [NextPositiveIdentity] [int] NOT NULL , CONSTRAINT [PK_TableIdentityValue] PRIMARY KEY CLUSTERED ( [TableName] ) ON [PRIMARY] ) ON [PRIMARY]GO
Now, depending on the type of data we are inserting into a table, we need to get either a negative or positive number for the PK. There are two sprocs that control the obtaining of those values:CREATE PROCEDURE GetNegativeIdentity @tableName varchar(50)AS DECLARE @nextNegativeIdentityValue int
BEGIN TRANSACTION SET TRANSACTION ISOLATION LEVEL SERIALIZABLE
SET @nextNegativeIdentityValue = ( SELECT NextNegativeIdentity FROM TableIdentityValue WITH (ROWLOCK) WHERE TableName = @tableName )
UPDATE TableIdentityValue SET NextNegativeIdentity = @nextNegativeIdentityValue - 1 WHERE TableName = @tableName
COMMIT TRANSACTION RETURN @nextNegativeIdentityValueGOCREATE PROCEDURE GetPositiveIdentity @tableName varchar(50)AS DECLARE @nextPositiveIdentityValue int
BEGIN TRANSACTION SET TRANSACTION ISOLATION LEVEL SERIALIZABLE
SET @nextPositiveIdentityValue = ( SELECT NextPositiveIdentity FROM TableIdentityValue WHERE TableName = @tableName )
UPDATE TableIdentityValue SET NextPositiveIdentity = @nextPositiveIdentityValue + 1 WHERE TableName = @tableName
COMMIT TRANSACTION RETURN @nextPositiveIdentityValueGOSo, the thing is, we need the read and update of the value from the specific TableIdentityValue row to be atomic - we don't want anyone else reading or modifying that data. The problem is knowing which level of isolation to use and/or locking, and how to implement that. I have tried a few different things that seemed to make sense, like placing a ROWLOCK on the SELECT statement, but is that lock going to hold for the entire length of the transaction? Also, I read that using some of the lock hints can be accomplished in the sense that some isolation levels are the same as some lock hints (e.g. setting isolation level to SERIALIZABLE "has the same effect as setting HOLDLOCK on all tables in all SELECT statements in a transaction" according to SQL Books Online.Any help is appreciated!
I have a question about the "readCommitted" transaction isolation level.I have a client that is updating a record on a table.I suspend the execution after the UPDATE but before the commit statement.Than another client is trying to read the same record.As transaction isolation is set to "readCommited" I expected that the secondclient will read the old version of the record (before the update).Instead, the second client hangs and wait until the first client do thecommit.I expect this behavior if transaction isolation is set to "serializable"Is this behavior correct?Thanks,D.
View 3 Replies View RelatedI vaguely remember reading somewhere that all distributed transactions are executed at Serializable Isolation Level "under the covers."
1. Is this true?
2. What does "under the covers" mean in this case; i.e. will I not see the isolation level represented accurately in requests?
Hello,
I have some locks issues on production database (win 2k3 SP1, sql server 2k5).
In fact, I have an asynchronous process that makes SELECT TOP 1 in a table and UPDATE the selected row. The transaction isolation level for doing this action is READUNCOMMITTED.
The isolation level readuncommitted is ignored for the update if I'm not wrong.
On the other hand, I have some transactional activities with the isolation level read uncommitted too.
But when I control the database activity, I find very often locks between the asynchronous part and the transactional part. This is the transactional activity that is locking the asynchronous activity.
The transactional activity is a simple SELECT and this type of query, in spite of the isolation level readuncommitted, makes exclusives locks when the asynchronous makes LCK_M_U.
I tried to modify the strored procedure for the SELECT/UPDATE of the asynchronous process with a "UPDATE my_table ... FROM my_table" query in order to reduce the transaction time. But the problem is always present.
Can someone help me to understand how a select query with the isolation level readuncommtted can make exclusives locks ?
Thanks in advance.
Hi,we are executing the following query in a stored procedure using snapshot isolation level:DELETE FROM tBackgroundProcessProgressReportFROM tBackgroundProcessProgressReport LEFT OUTER JOIN tBackgroundProcess ON
tBackgroundProcess.BackgroundProcessProgressReportID =
tBackgroundProcessProgressReport.BackgroundProcessProgressReportID LEFT
OUTER JOIN tBackgroundProcessProgressReportItem ON
tBackgroundProcessProgressReport.BackgroundProcessProgressReportID =
tBackgroundProcessProgressReportItem.BackgroundProcessProgressReportIDWHERE (tBackgroundProcess.BackgroundProcessID IS NULL) AND (tBackgroundProcessProgressReportItem.BackgroundProcessProgressReportItemID IS NULL)The query should delete records from tBackgroundProcessProgressReport which are not connected with the other two tables.However, for some reasone we get the following exception:System.Data.SqlClient.SqlException:
Snapshot isolation transaction aborted due to update conflict. You
cannot use snapshot isolation to access table 'dbo.tBackgroundProcess'
directly or indirectly in database 'RHSS_PRD_PT_Engine' to update,
delete, or insert the row that has been modified or deleted by another
transaction. Retry the transaction or change the isolation level for
the update/delete statement.The exception specifies that we are
not allowed to update/delete/insert records in tBackgroundProcess, but
the query indeed deletes records from tBackgroundProcessProgressReport,
not from the table in the exception.Is the exception raised because of the join?Has someone encountered this issue before?Thanks,Yani
We have a service that inserts some rows into a parent table (P) and child table (C). This operation is atomic and performed within a transaction.
We also have a service that queries these tables such that rows are (should only be) returned from P where there are no children for that parent.
The SQL that performs this is simplified below:
SELECT P.SomeCol
FROM P
LEFT OUTER JOIN C ON P.PKofP_Value = C.PkofP_Value
WHERE
C.PkofPValue IS NULL
AND P.SomeOtherCol=0
Our expectation is that the query service should only return rows from P where there are no rows in C.
However, this seems not to be the case, and occasionally we find that rows from P are returned where there are matching rows in C.
We are sure that the process that inserts rows into P and C does so within a single transaction.
We have traced this with SQLTrace and can see the txn stag and committing and all operations using the same transactionid within the transaction.
We are running the default isolation level committed.
In SQLTrace we can see the query process start, the inserter process start and complete and then the query process continue (after presumably being blocked).
So how can the query process "miss" the child rows and return the parent from the above query?
Is it possible that, in this isolation level, the inserter process can block the query process such that when the inserter process commits and when the query process continues it does not see the child rows inserted because they were inserted in the table/index "behind" where the query process has already read - some kind of phantom phenomenon?
Dear all,
We have connected a Access to a MS SQL Server 2005 as a Linked Server with the followoing settings:
1) Provider: Microsoft Jet 4.0 OLE DB Provider
2) Product Name: Access
3) Data source: X:XXXXX.mdb
4) Provider string: ;pwd=YYYYYY;
5) Collation Compatible: False
6) Data Access: True
7) Rpc: False
8) Rpc Out: False
9) Use Remote Collation: True
10) Collation Name:
11) Connection Timeout: 0
12) Query Timeout: 0
We found that when cannot have any insert/update/delete statement for this linked server if transaction is began. Otherwise, we will have the following exception.
============
Msg 7390, Level 16, State 2, Line 1
The requested operation could not be performed because OLE DB provider "Microsoft.Jet.OLEDB.4.0" for linked server "ZZZZZZ" does not support the required transaction interface.===========
We wonder whether the problem is because Access does not support distributed transaction. If so, do you know any workaround will work for us?
Thanks and regards,
William
I've recently started working with a public sector organisation who have 4 clustered sql instances that has 80% of it's db mirrored.
Looking at the transaction log - it seems that a transaction log backup is a good idea as the log is 4x larger than the data file.But I'm not allowed access to the physical server to check onto which drive I can create the trn. No RDP, no vmware - let's be honest I'm not even allowed to launch cmd line Also the Server Manager informs me "We will need to carefully look at database backups if you guys want to start doing these backups on box, as that will break our off box backup routine (it will screw the transaction chain)."
I don't understand how backing up the transaction log could break the "transaction chain"?
We are using sql 2008r2 standard edition.One of our Production database is using default isolation Readcommitted.The transactions also using read committed. But we want change isolation level to read comitted snapshot isolation and test it to avoid deadlocks.
Is it possible to set in the transaction level for some queries or do we need to change entire database isolation level by using alter database "ALTER DATABASE AdventureWorks2008R2 SET READ_COMMITTED_SNAPSHOT ON"
I have several databases set to read committed snapshot isolation level. Tempdb is configured according to best practices, but I don't see it's used much.
The application uses EF6, and it calls the stored procedures in the following way
Database.ExecuteSqlCommandAsync("exec dbo.spSync_MatchesByTenant @MatchesGroup, @TenantId", parameter, licenseIDParam);
Is it possible the code does not use the read committed snapshot isolation level of the database?
i use a single stored procedure to update many tables in sql server 2014 database, using defalut transaction isolation level we got random performance issues.
maybe it would better to use read uncommitted isolation level?
what's happens ,in the both cases( read committed, uncommitted) if the sp is called at the same time passing the same @key parameter?
this is a sample to show of the real stored procedure works:
CREATE PROCEDURE SP_Test
@Key int,
@Values1 Values1 readonly,
@Values2 Values2 readonly,
@Values3 Values3 readonly
[code]....
We are getting frequently blocking in Report server database.
Is it ok to change isolation level to RCSI for report server database?
here's a question i've always wondered the answer to,
you have a transaction log on sql 2000 which supposedly records all the sql commands (select, delete, insert, update) that are performed on your database.
now say you use ODBC and Microsoft ACCESS, you create a database file in Microsoft ACCESS with linked tables to your SQL Database via an ODBC connection.
now say you alter the data, maybe delete some records from that sql database using your linked table in Microsoft ACCESS
Would SQL 2000 (or any other version) record these actions in the log, even though the actions were carried out in Microsoft ACCESS? or has doing this completely negated the security offered by the transaction log feature?
do hope someone could shed some light on this, it's been bothering me for a while
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.
View 8 Replies View RelatedI have a problem when trying to save a transaction remotely. I'm using my pc as the server and I can save without any problem from local (the same project).
But when I try accessing the project from other pc, the transaction doesn't get saved into the db.
No error displayed. It's just doesn't get saved. What is the problem? Is there any IIS setting that I should put in?
Hello,
I have microsoft access database. I want to use this database as source of SSIS transformation.
I have a data flow task which I want to get executed in Transaction with TransactionOption as "Required".
I tried using OLEDB datasource which uses oledb connection. I also tried using ADO.NET connection type with DataReader DataSource.
But in all cases at run time, it fires an error message as follows:
[DataReader Source [1]] Error: System.InvalidOperationException: The ITransactionLocal interface is not supported by the 'Microsoft.Jet.OLEDB.4.0' provider. Local transactions are unavailable with the current provider. at System.Data.OleDb.OleDbConnectionInternal.EnlistTransactionInternal(Transaction transaction, Boolean forcedAutomatic) at System.Data.OleDb.OleDbConnectionInternal.EnlistTransaction(Transaction transaction) at System.Data.OleDb.OleDbConnection.EnlistTransaction(Transaction transaction) at Microsoft.SqlServer.Dts.Runtime.ManagedHelper.GetManagedConnection(String assemblyQualifiedName, String connStr, Object transaction) at Microsoft.SqlServer.Dts.Runtime.Wrapper.IDTSConnectionManager90.AcquireConnection(Object pTransaction) at Microsoft.SqlServer.Dts.Pipeline.DataReaderSourceAdapter.AcquireConnections(Object transaction) at Microsoft.SqlServer.Dts.Pipeline.ManagedComponentHost.HostAcquireConnections(IDTSManagedComponentWrapper90 wrapper, Object transaction)
If I remove the transaction, the data flow task works perfectly fine.
Please suggest What mistake I am doing while connecting to MS Access database in side transaction??
The same mentioned configuration WITH TRANSACTION works perfectly fine for SQL Server AS SOURCE. Am I missing some very obvious thing??
Please suggest.
Hi,
I am having a application in which from the front end i am saving details of three different things
i.Enquiry Details
ii.Parts Details
iii.Machine details
i am saving the Enquiry detail in a data table,Parts Details in a data table and machine detail in a data table and finally i am adding the three data tables into a single data set and passing the data set to data access layer there i have three insert command one for each data table in my case the enquiry data table will be saved first and then the next two details will be saved and i am saving the details in three different tables in the database, my problem is some times the enquiry details will save to the database and while saving the Parts details there may be some exception and i will throw an exception in that case the enquiry details will be saved and the remaining two details are not saved(Which are also part of the same Transaction).I wanted to know about how to call the transaction function in case of Data Access Layer.
Hi All
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.
Please help me it's very urgent.
I read about isolation levels... good, how can I set a proper isolation if I have 100 transactions... What is the aproche?:shocked:
View 1 Replies View RelatedI 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?!