Millions of rows returned during Nested Loop

 Hi,

Would someone please offer an explanation - I am trying to understand why there is a row output multiplication effect during a Hash Group By in the following case:

Select *

FROM    CRMFO300 crm300,

        (

                SELECT  REPAIR_ORDER_NBR,

                        DEALER_CODE     ,

                        TRANS_DATE

                FROM    CRMFO300

                WHERE   REPAIR_ORDER_AUDIT_ID = 4589310

        )

        repair

WHERE   repair.REPAIR_ORDER_NBR = crm300.REPAIR_ORDER_NBR

        AND repair.DEALER_CODE  = crm300.DEALER_CODE

        AND TO_CHAR(crm300.TRANS_DATE,'YYYYMMDDSSSSS')

        ||

        LPAD(REPAIR_ORDER_AUDIT_ID, 20, 0) =

        (

                SELECT  MAX(TO_CHAR(TRANS_DATE, '"YYYYMMDDSSSSS"')

                        ||

                        LPAD(REPAIR_ORDER_AUDIT_ID, 20,0))

                FROM    CRMFO300 crm300b

                WHERE   repair.REPAIR_ORDER_NBR    = crm300b.REPAIR_ORDER_NBR