178. All the database users are presently connected to the database instance and working. The HR user
has opened three database sessions and executed the following command in one of his sessions:
SQL> UPDATE persons SET ccode='U031' WHERE ccode='U029';
123 rows updated.
SQL> DELETE FROM persons WHERE exp='Y';
3 rows deleted.
The SYS user opens a new session after HR executed the above commands. Which sessions can see
the effect of the UPDATE and DELETE commands?
A.all sessions of the HR user only
B.all sessions of the HR user and the SYS user
C.the session of the HR user that executed the commands
D.all the sessions for which the database users have access privilege to the PERSONS table
Answer: C
答案解析：
因为在update和delete后没有提交，所以只有执行了这两条语句的session才能看见这两条语句执行后的结果。