How do I speed up a union query in Oracle database?

SELECT EXCEPTION_TYPE, 
NVL(LAST_CHG_DATE, TRUNC(SYSDATE)) LAST_CHG_DATE, HOUSE, CUST,
(CASE WHEN OPER = 'D80' THEN '000' ELSE OPER END) OPER,
(CASE WHEN OPER_NAME = 'USER-ITCDEMO' THEN 'UNKNOWN' ELSE OPER_NAME END) OPER_NAME
FROM
(SELECT EXCEPTION_TYPE, LAST_CHG_DATE, HOUSE, CUST, OPER, OPER_NAME from EXCEPT_HSI_PHONE_ONLY_CHG
WHERE HOUSE <> '118247'
UNION ALL
SELECT EXCEPTION_TYPE, LAST_CHG_DATE, HOUSE, CUST, OPER, OPER_NAME FROM EXCEPT_MULT_VID_PKG
WHERE HOUSE <> '118247'
UNION ALL
SELECT EXCEPTION_TYPE, LAST_CHG_DATE, HOUSE, CUST, OPER, OPER_NAME FROM EXCEPT_MULT_VID_SERV
WHERE HOUSE <> '118247'
UNION ALL
SELECT EXCEPTION_TYPE, LAST_CHG_DATE, HOUSE, CUST, OPER, OPER_NAME FROM EXCEPT_MULT_VID_BUS
UNION ALL
WHERE HOUSE <> '118247'
SELECT EXCEPTION_TYPE, LAST_CHG_DATE, HOUSE, CUST, OPER, OPER_NAME FROM EXCEPT_NO_DVR_CHG
WHERE HOUSE <> '118247'
UNION ALL
SELECT EXCEPTION_TYPE, LAST_CHG_DATE, HOUSE, CUST, OPER, OPER_NAME FROM EXCEPT_DIG_ST_CHG
WHERE HOUSE <> '118247'
UNION ALL
SELECT EXCEPTION_TYPE, LAST_CHG_DATE, HOUSE, CUST, OPER, OPER_NAME FROM EXCEPT_SEASONAL
WHERE HOUSE <> '118247'
UNION ALL
SELECT EXCEPTION_TYPE, LAST_CHG_DATE, HOUSE, CUST, OPER, OPER_NAME FROM EXCEPT_TENANT_CHG
WHERE HOUSE <> '118247'
UNION ALL
SELECT EXCEPTION_TYPE, LAST_CHG_DATE, HOUSE, CUST, OPER, OPER_NAME FROM EXCEPT_XF_MISSING
WHERE HOUSE <> '118247'
UNION ALL
SELECT EXCEPTION_TYPE, LAST_CHG_DATE, HOUSE, CUST, OPER, OPER_NAME FROM EXCEPT_XG_MISSING
WHERE HOUSE <> '118247'
UNION ALL
SELECT EXCEPTION_TYPE, LAST_CHG_DATE, HOUSE, CUST, OPER, OPER_NAME FROM EXCEPT_NO_SUBWISE
WHERE HOUSE <> '118247'
UNION ALL
SELECT EXCEPTION_TYPE, LAST_CHG_DATE, HOUSE, CUST, OPER, OPER_NAME FROM EXCEPT_NO_SALES_REP
WHERE HOUSE <> '118247'
UNION ALL
SELECT EXCEPTION_TYPE, LAST_CHG_DATE, HOUSE, CUST, OPER, OPER_NAME FROM EXCEPT_CANCEL_NP
WHERE HOUSE <> '118247'
UNION ALL
SELECT EXCEPTION_TYPE, LAST_CHG_DATE, HOUSE, CUST, OPER, OPER_NAME FROM EXCEPT_PREF_NEW_VIDEO_ONLY
WHERE HOUSE <> '118247'
UNION ALL
SELECT EXCEPTION_TYPE, LAST_CHG_DATE, HOUSE, CUST, OPER, OPER_NAME FROM EXCEPT_PREF_NO_3BRONZE
WHERE HOUSE <> '118247'
UNION ALL
SELECT EXCEPTION_TYPE, LAST_CHG_DATE, HOUSE, CUST, OPER, OPER_NAME FROM EXCEPT_BUS_LITE
WHERE HOUSE <> '118247'
)

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