Lot number problem with Delivery in Query

Hi Team,

I need to get lot number based on delivery number but I'm not sure why data is not showing some times also query is taking so much of time.Please help.

SELECT 

  wnd.delivery_id,

        wdd.delivery_detail_id,

  ool.line_id order_line_id,

  wdd.item_description item_name,

        wdd.inventory_item_id item_id,

        mln.gen_object_id lot_id,

        mtln.lot_number,

        mmt.trx_source_line_id

   FROM wsh_delivery_details wdd,

        mtl_material_transactions mmt,

        mtl_transaction_lot_numbers mtln,

        mtl_lot_numbers mln,

  wsh_delivery_assignments wda,

        wsh_new_deliveries wnd,

        oe_order_lines_all ool