You can try to use serializable transaction isolation when configuring the data source. This is the highest isolation level and avoids dirty reads, non-repeatable reads, and phantom reads by locking range of rows or the entire tables.
You can also create a view from the ‘create a base view using the query’ option. In this option, the query can be directly executed from the SQL server. This way you would be able to execute all database specific syntax on VDP admin tool. But this would not be the best practice in general as there might be a potential risk of disabling the delegations of other functions.
Hope this helps!