Override Query of Form Data Source

Hi all,

How can I override the query of the form data source?

I need to remove the firstFast in the Select statement. I've checked the query in AOT and its firstFast property is set to no yet when I debugged it, its statement has firstFast in it. This is the SQL statement I get 

SELECT FIRSTFAST * FROM CustTransOpen(CustTransOpen) ..... and SO ON

Best regards