Oracle 21c

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CREATE TABLE tab(
    Id       INT,
    Value_   INT
);
INSERT ALL
    INTO tab VALUES (1,  	 1)
    INTO tab VALUES (1, 	 1)
    INTO tab VALUES (2, 	10)
    INTO tab VALUES (2, 	10)
SELECT * FROM DUAL;
4 rows affected

SELECT tab.*, SUM(Value_) OVER(PARTITION BY Id) AS sum_
FROM tab


ID
VALUE_
SUM_


1
1
2

1
1
2

2
10
20

2
10
20