1) There is no way to configure a different isolation level for report definitions that what is defined on the data source.
2) Report definitions do not allow for customization of the SQL generated. Please let me know your use case on why you do need to customize. Is there a SQL that report definition configuration is unable to generate?
So as I understand, you want to display the assignments, for a given user, even if a different transaction may have deleted the same entries in that table? Why would you want to do that?
As I said before, we currently don't have a way to set the isolation level to allow for dirty reads. Even with list views, unless you are acquiring your own database connection to execute the query, there is no way to change the isolation level on the connection.
I didn't think you needed to get a lock when you run a report. Also, back when report rules were list view rules, you could specify your own get-content activity. Can you still do that with report rules ? /Eric
There are often requirements to implement custom report functionality for business where the underlying report definition may take longer to complete, e.g. 1 minute while it must still allow intensive case update to happen. Since typical SQL SELECT will acquire a shared lock by default, an option to suppress this will be very useful to prevent any performance degradation while the report is running.