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【Oracle 12c】CUUG OCP認證071考試原題解析(32)

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32.choose the best answer

View the Exhibit and examine the data in EMP and DEPT tables.

In the DEPT table, DEPTNO is the PRIMARY KEY.

In the EMP table, EMPNO is the PRIMARY KEY and DEPTNO is the FOREIGN KEY referencing

the DEPTNO column in the DEPT table.

What would be the outcome of the following statements executed in the given sequence?

DROP TABLE emp;

FLASHBACK TABLE emp TO BEFORE DROP;

INSERT INTO emp VALUES (2,‘SCOTT‘, 10);

INSERT INTO emp VALUES (3,‘KING‘, 55);

A) Both the INSERT statements would succeed because none of the constraints on the table are automatically retrieved when the table is flashed back.

B) Only the second INSERT statement would succeed because all the constraints except referential integrity constraints that reference other tables are retrieved automatically after the table is flashed back.

C) Both the INSERT statements would fail because all constraints are automatically retrieved when the table is flashed back.

D) Only the first INSERT statement would succeed because all the constraints except the primary key constraint are automatically retrieved after a table is flashed back.

Answer:B

(解析:除了引用其他表的引用完整性約束之外,所有約束在表被閃回之後自動恢復,已經做過實驗)

【Oracle 12c】CUUG OCP認證071考試原題解析(32)