What happens if a Data Flow Task has the IsolationLevel property set to "Serializable", but has a query in an OLEDB Source with "NoLock"?

I'm a bit late to the conversation, but filling in the answer, so the search engines will direct people in the right direction. The IsolationLevel property only works on distributed transactions (ie. TransactionOption=Required), so it doesn't conflict in practice with query hints very often because not a whole lot of designs use transactions. I suspect your query hint will win if transactions are in use and the IsolationLevel is obeyyed by SSIS. You can see the queries using SQL Profiler, and note the Audit Login event where the isolation level is configured via a SET statement. The documentation I wrote was best captured in this forum post http://social.msdn.microsoft.com/Forums/en-US/sqlintegrationservices/thread/3dcea5f6-32ef-40aa-90d5-0f2fef9e1d38 http://connect.microsoft.com/SQLServer/feedback/details/498891/ssis-setting-isolationlevel-to-readuncommitted-still-uses-read-committed You can vote on this item if you want to ask for improvement. Best Regards, Jason Didn't get enough help here? Submit a case with the Microsoft Customer Support team for deeper investigation - http://support.microsoft.com/select/default.aspx?target=assistance