We have a ETL job with merge statement. It was working fine earlier. There was a node eviction on last week and due to that the DB was bounced. After bouncing the DB the procedure started failing with ORA-08006 error. Same error is appearing when we try to run the statement manually. Below is the statement:

DECLARE
LV_SR_SYSTEM_ID NUMBER;
LV_SR_SYS_ID NUMBER;
BEGIN
SELECT DISTINCT SOURCE_SYSTEM_ID
INTO LV_SR_SYSTEM_ID
FROM DM_SOURCE_ENTITY
WHERE UPPER(SOURCE_SYSTEM_NAME)='CLSSC';
SELECT DISTINCT SOURCE_SYSTEM_ID
INTO LV_SR_SYS_ID
FROM DM_SOURCE_ENTITY
WHERE UPPER(SOURCE_SYSTEM_NAME)='INTREPID';


MERGE INTO DM_SERVICE_ORDER A USING
(SELECT
A.ID AS SOF_ID,
NULL AS ID,
B.SALES_ORDER_ID AS ORDER_ID,
B.ORDER_MANAGER AS ORDER_MANAGER,
B.ORDER_STATUS AS ORDER_STATUS ,
B.ORD_TYPE AS ORDER_TYPE,
B.MDD AS MDD,
LV_SR_SYSTEM_ID AS SOURCE_SYSTEM_ID
FROM (select id,service_order_id,row_number() over (partition by service_order_id
order by id desc ) rn
from f_service_order
where service_order_id is not null
) A,
TBL_BI_CLA_SVC_ORD B
WHERE A.SERVICE_ORDER_ID =B.SALES_ORDER_ID
AND A.RN=1
) B
ON (A.SOF_ID=B.SOF_ID AND A.ORDER_ID=B.ORDER_ID AND A.SOURCE_SYSTEM_ID=B.SOURCE_SYSTEM_ID
AND (A.ID IS NULL AND B.ID IS NULL)
)
WHEN MATCHED THEN
UPDATE SET
-- A.ORDER_ID=B.ORDER_ID ,
A.ORDER_MANAGER=A.ORDER_MANAGER,
A.ORDER_TYPE=A.ORDER_TYPE,
A.MDD=B.MDD,
-- A.SOURCE_SYSTEM_ID=SOURCE_SYSTEM_ID,
A.EDW_UPDATE_DATE=SYSDATE

WHEN NOT MATCHED THEN
INSERT (
A.ROW_ID,
A.SOF_ID,
A.ID,
A.ORDER_ID,
A.ORDER_MANAGER,
A.ORDER_STATUS,
A.ORDER_TYPE,
A.MDD,
A.SOURCE_SYSTEM_ID,
A.EDW_UPDATE_DATE,
A.EDW_CREATE_DATE
)
VALUES
(
DM_SERVICE_ORDER_SEQ.NEXTVAL,
B.SOF_ID,
B.ID ,
B.ORDER_ID,
B.ORDER_MANAGER,
B.ORDER_STATUS,
B.ORDER_TYPE,
B.MDD,
B.SOURCE_SYSTEM_ID,
SYSDATE,
SYSDATE
);
COMMIT;
END;

Error report:
ORA-08006: specified row no longer exists
ORA-06512: at line 16
08006. 00000 - "specified row no longer exists"
*Cause: the row has been deleted by another user since the operation began
*Action: re-try the operation

SQL> create table t (pk number primary key, x number)
  2      partition by list (pk)
  3      (partition p1 values(1),
  4       partition p2 values(2)
  5      )
  6  enable row movement;

Table created.

SQL>
SQL> insert into t values (1, 1);

1 row created.

SQL> commit;

Commit complete.

SQL>
SQL> merge into t
  2  using (select 1 idx, 2 new_val from dual
  3         connect by level <= 2
  4        ) u
  5  on (t.x = u.idx)
  6  when matched then
  7    update set pk=new_val;
merge into t
           *
ERROR at line 1:
ORA-08006: specified row no longer exists


SQL>
SQL>