DB QUERY IN ORACLE - duplicates

Question

SELECT
BILLS.*
FROM
BATELCO_BILLS_S BILLS
INNER JOIN
(
SELECT
BTL_BILL_I_NUMBER,
MAX(R_MODIFY_DATE) AS MAXDATETIME
FROM
BATELCO_BILLS_S
GROUP BY
BTL_BILL_I_NUMBER
) GROUPEDBILLS
ON BILLS.BTL_BILL_I_NUMBER = GROUPEDBILLS.BTL_BILL_I_NUMBER AND
BILLS.R_MODIFY_DATE = GROUPEDBILLS.MAXDATETIME
WHERE
(BILLS.BTL_BILL_I_CPR = :B3 OR BILLS.BTL_BILL_C_CPR = :B3) AND
(TO_DATE(BTL_BILL_I_DATE) BETWEEN TO_DATE(:B2, 'dd/mm/yyyy') AND
TO_DATE(:B1, 'dd/mm/yyyy') OR
TO_DATE(BTL_BILL_C_DATE) BETWEEN TO_DATE(:B2, 'dd/mm/yyyy') AND
TO_DATE(:B1, 'dd/mm/yyyy'))
Please help to get optimize the query by avoiding the join so that GROUP BY is required.
AVOID DUPLICATE BTL_BILL_I_NUMBER AND FETCH THE RESULTS.

Answer 1

You could rewrite this using an analytic function, such as ROW_NUMBER:
SELECT *
FROM
(
SELECT *,
ROW_NUMBER() OVER (PARTITION BY BTL_BILL_I_NUMBER
ORDER BY R_MODIFY_DATE DESC) rn
FROM BATELCO_BILLS_S
WHERE
(BTL_BILL_I_CPR = :B3 OR BTL_BILL_C_CPR = :B3) AND
(TO_DATE(BTL_BILL_I_DATE) BETWEEN TO_DATE(:B2, 'dd/mm/yyyy') AND
TO_DATE(:B1, 'dd/mm/yyyy') OR
TO_DATE(BTL_BILL_C_DATE) BETWEEN TO_DATE(:B2, 'dd/mm/yyyy') AND
TO_DATE(:B1, 'dd/mm/yyyy'))
) t
WHERE rn = 1;
I'm not an expert in Oracle's syntax, and the SELECT * calls I have above may not work. If not, then you can (and rightfully should) list out the columns you want to actually select.

Answer 2

I am not an oracle expert but here is what I would have done:
Avoid using * in the selected columns, instead mention each and every column you need;
No need of join. You are working on the same table (see below example);
Add index to the column used in where clause
SELECT BILLS.btl_bill_i_number, Max(r_modify_date) AS MAXDATETIME
FROM batelco_bills_s BILLS
GROUP BY btl_bill_i_number
WHERE ( BILLS.btl_bill_i_cpr = :B3
OR BILLS.btl_bill_c_cpr = :B3 )
AND ( To_date(btl_bill_i_date) BETWEEN To_date(:B2, 'dd/mm/yyyy') AND To_date(:B1, 'dd/mm/yyyy')
OR To_date(btl_bill_c_date) BETWEEN To_date(:B2, 'dd/mm/yyyy') AND
To_date(:B1, 'dd/mm/yyyy') )
Hope this helps :)