SQL & PL/SQL

I have a table which stores the customer , related customer  and count of related customers.

The related customer can have again further related customers it's like a recursive relationships.

I wanted to find out all the related customers ( till the last related customer ) for a customer.

I had tried something like below which was giving me an error loop in user data

select *

  from (select connect_by_root(cus_id) cus_id, rel_cus_id

          from RELATED_TABLE

         start with rel_cus_id is not null

        connect by prior cus_id = rel_cus_id)

where cus_id <> rel_cus_id;

Table stats :-

---------------

Present volume is 2,00,000 records .

Create table

--------------

CREATE TABLE RELATED_TABLE

( CUS_ID            VARCHAR2(09) ,

  REL_CUS_ID        VARCHAR2(09) ,

  COUNT_OF_REL_CUST NUMBER(12)) ;

Sample data:-

--------------- 

INSERT INTO RELATED_TABLE VALUES ('402758970','898196448',3);

INSERT INTO RELATED_TABLE VALUES ('402758970','855115206',3);

INSERT INTO RELATED_TABLE VALUES ('402758970','850353774',3);

INSERT INTO RELATED_TABLE VALUES ('898196448','691094946',3);

INSERT INTO RELATED_TABLE VALUES ('898196448','404636299',3);

INSERT INTO RELATED_TABLE VALUES ('898196448','402758970',3);

INSERT INTO RELATED_TABLE VALUES ('855115206','870397045',3);

INSERT INTO RELATED_TABLE VALUES ('855115206','855115206',3);

INSERT INTO RELATED_TABLE VALUES ('855115206','402758970',3);

CUS_ID     REL_CUS_ID    COUNT_OF_REL_CUST  

402758970  898196448       3                                                         

402758970  855115206       3                                                         

402758970  850353774       3                                    

898196448  691094946       3                                    

898196448  404636299       3                                    

898196448  402758970       3                                           

855115206  870397045       3                                           

855115206  855115206       3                                           

855115206  402758970       3

OUTPUT:-

--------------------

402758970  898196448

402758970  855115206

402758970  850353774

402758970  691094946

402758970  404636299

402758970  870397045

402758970  855115206