Hello I'm having problems getting my head round why this is happening. Pretty sure I understand the theory, but something else must be going on that I don't see. Table A has the following schema: ID [Primary Key] Name Type [Foreign Key] SprocA sets Isolation Level to Repeatable Read, and Selects rows from Table A that have Type=1. ...
How do I set the isolation level of a transaction to 'SERIALIZABLE' in PHP using mysqli? I have looked everywhere and I can't find any information on it. Here is an explanation of the isolation levels. ...
Is there a way to specify the transaction isolation level when Crystal Reports queries a SQL Server 2005 database without resorting to any of the following: Encapsulating the report's query in a stored procedure that executes SET TRANSACTION ISOLATION LEVEL... before the query itself Hand-writing the SQL query in Crystal Reports to exe...
Hi, I need some clarification how MS-DTC will behave in scenario given below 1) I have more than one connection in within a transactionscope (Isolation level - ReadCommited),which will bring MS- DTC into action now : a) Will MS-DTC automatically change isolation level to SERIALIZABLE. b) (Imp) If above answer is yes and I have imple...
I want to convert a table storing in Name-Value pair data to relational form in SQL Server 2008. Source table Strings ID Type String 100 1 John 100 2 Milton 101 1 Johny 101 2 Gaddar Target required Customers ID FirstName LastName 100 John Milton 101 Johny Gaddar I am following the strategy given below, Populate the Customer t...
I develop C# window application with Microsoft SQL Server 2005 sp3. My Application has ploblem while one of client save Order Document. Another client cannot select data from Order table util saving process is complete. I used Transaction and Isolation=ReadUncommit to save Order Document. My Application has 3 table is OrderHd, OrderLine ...
Using SQL2k5, I have a staging table that contains columns that will populate numerous other tables. For instance, a statement like this: INSERT INTO [appTable1] ([colA], [colB]) SELECT [appTable1_colA], [appTable1_colB] FROM [stageTable] A trigger on [appTable1] will then populate the identity column values of the newly inserted ...
Hello, While investigating a problem I believed to be related to lock escalation and thinking that READ_COMMITTED_SNAPSHOT would be the solution, I checked whether it was already enabled. To my surprise, the database had compatibility level 80 (SQL Server 2000, and I'm new here, and nobody or document seems to know why!). But READ_COM...
Hello Trying to completely understand SQL Server Isolation Levels - notably REPEATABLE READ. I have a sproc that starts a transaction and puts a cursor around some data (boo hiss). This can be a fair chunk of data, so can take a while to do. It will then COMMIT or ROLLBACK. During this time, before the transaction has been closed, i...
We're evaluating EF4 and my DBA says we must use the NOLOCK hint in all our SELECT statements. So I'm looking into how to make this happen when using EF4. I've read the different ideas on how to make this happen in EF4, but all seem like a work around and not sanctioned by Microsoft or EF4. What is the "official Microsoft" response to...
What are the risks or performance degradation when using SET TRANSACTION ISOLATION LEVEL REPEATABLE READ? We have some SP that are called from BizTalk services. We are getting deadlock sometimes. If we change the isolation level, what are the risks and possible perfomance degradations? ...
Hello, I'm trying to execute a simple select query using IfxCommand. I would like to set isolation to dirty read, but I have only found examples of setting isolation level in the context of an IfxTransaction. I do not require a transaction as I am only issuing a select statement. Below is my current code, is this the best approach? Also,...
Is it true that "Every statement (select/insert/delete/update) has an isolation level regardless of transactions"? I have a scenario in which I have set update of statements inside a transaction (ReadCommitted). And another set not in a transaction (select statements). In this case when first set is executing another waits. If I set R...
Do you know the default isolation level of the transactions used in Django? Is it possible to set the isolation level in the database independent way? I'm mainly interested in mysql and postgres. ...
I am using sqlite for test cases in a project that leverages NHibernate. Everything is working great, except when I try to create a ReadUncommitted transaction: e.g. Session.BeginTransaction(System.Data.IsolationLevel.ReadUncommitted) The error message is: "isolationLevel" (thats it) The call stack looks like: at System.Data.S...
Hi, I'm trying to get a handle on whether we have a problem in our application with database connections using incorrect IsolationLevels. Our application is a .Net 3.5 database app using SQL Server 2005. I've discovered that the IsolationLevel of connections are not reset when they are returned to the connection pool (see here) and ...
When measuring performance on my query I came up with a dependency between isolation level and elapsed time that was surprising to me READUNCOMMITTED - 409024 READCOMMITTED - 368021 REPEATABLEREAD - 358019 SERIALIZABLE - 348019 Left column is table hint, and the right column is elapsed time in microseconds (sys.dm_exec_query_stats.tot...
In plan English what are the disadvanges and advantages of using SET TRANSACTION ISOLATION LEVEL READ UNCOMMITTED in query for .NET applications and reporting services application? ...
Middle-tier component will execute the data access routines in application. The component will call several SQL Server stored procedures to perform database updates. All of these procedure calls run under the control of a single transaction. The code for the middle-tier will implement the following objects: SqlCommand comm = connection....
I have a process which is called from multiple threads which does the following: Start transaction Select unit of work from work table with by finding the next row where IsProcessed=0 with hints (UPDLOCK, HOLDLOCK, READPAST) Process the unit of work (C# and SQL stored procedures) Commit the transaction The idea of this is that a thre...