SQLP CBT 기출문제 예상문제 456번

다음 문제를 풀어보세요.

다음 SQL 중 인덱스 스캔 효율을 저해할 가능성이 가장 높은 것을 고르시오.

[테이블 구조]
CREATE TABLE ORDERS (
  ORDER_ID NUMBER PRIMARY KEY,
  CUSTOMER_ID NUMBER,
  ORDER_DATE DATE,
  AMOUNT NUMBER,
  STATUS VARCHAR2(10)
);

CREATE INDEX IDX_ORDERS_CUSTOMER_DATE ON ORDERS (CUSTOMER_ID, ORDER_DATE);

SELECT * FROM ORDERS WHERE CUSTOMER_ID = 100 AND ORDER_DATE > SYSDATE - 7;

SELECT * FROM ORDERS WHERE CUSTOMER_ID = 100;

SELECT * FROM ORDERS WHERE TO_CHAR(ORDER_DATE, 'YYYY') = '2023';

SELECT CUSTOMER_ID, ORDER_DATE FROM ORDERS WHERE CUSTOMER_ID < 200 ORDER BY CUSTOMER_ID, ORDER_DATE;