oracle - Script (or my logic in code) is causing deadlocks -

below see stored procedure causes locks in oracle 11. unfortunately in corporate environment doesn't allow me access trace logs, or anything. i've read tons of recommendations how that, , cry can't it. i'm not sure can determine below if culprit. anyway, everyone's time.

merge my_owner.my_table tgtt   using (select ditt, siscd my_owner.ngr_dmnsn_typ     dmnsn_nm_txt = 'myname'     , siscd = 'refdb') srct   on ( tgtt.ditt = srct.ditt , tgtt.id_txt = 50000 )   when matched     update set tgtt.dscrptn_txt = 'dfdf', tgtt.nm_txt = 'bldfdfah'   when not matched        insert (tgtt.dscrptn_txt, tgtt.nm_txt, tgtt.ditt, tgtt.id_nbr, tgtt.id_txt)       values ('ee', 'ee', srct.ditt, 50000, '50000' );