多选题

User SCOTT executes the following command on the EMP table but has not issued COMMIT, ROLLBACK, orany data definition language (DDL) command: SQL> SELECT ename FROM emp WHERE job=’CLERK’ FOR UPDATE OF empno; SCOTT has opened another session to work with the database instance.  Which three operations would waitwhen issued in SCOTT’s second session()

ALOCK TABLE emp IN SHARE MODE;

BLOCK TABLE emp IN EXCLUSIVE MODE;

CUPDATE emp SET sal=sal*1.2 WHERE job=ANAGER?UPDATE emp SET sal=sal*1.2 WHERE job=?ANAGER?

DINSERT INTO emp(empno,ename) VALUES (1289,’Harry’);

ESELECT ename FROM emp WHERE job=’CLERK’ FOR UPDATE OF empno

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答案解析