SQLD 기출문제 예상문제 271번

다음 문제를 풀어보세요.

다음 중 아래 SQL 쿼리에 대한 설명으로 가장 적절한 것을 고르시오.

[테이블 구조]

CREATE TABLE EMPLOYEES (
    EMP_ID    VARCHAR2(10) PRIMARY KEY,
    EMP_NAME  VARCHAR2(100),
    DEPT_ID   VARCHAR2(10),
    SALARY    NUMBER
);

INSERT INTO EMPLOYEES VALUES ('E001', '김철수', 'D10', 5000);
INSERT INTO EMPLOYEES VALUES ('E002', '이영희', 'D10', 4500);
INSERT INTO EMPLOYEES VALUES ('E003', '박민수', 'D20', 6000);
INSERT INTO EMPLOYEES VALUES ('E004', '최지영', 'D10', 4500);
INSERT INTO EMPLOYEES VALUES ('E005', '정대현', 'D20', 5500);
INSERT INTO EMPLOYEES VALUES ('E006', '이지은', 'D30', 4000);

[SQL 쿼리]

SELECT
    EMP_NAME,
    DEPT_ID,
    SALARY,
    ROW_NUMBER() OVER (PARTITION BY DEPT_ID ORDER BY SALARY DESC) AS RNK_ROW_NUMBER,
    RANK() OVER (PARTITION BY DEPT_ID ORDER BY SALARY DESC) AS RNK_RANK
FROM
    EMPLOYEES;