一个关于session的数据库问题，请教！

Question

时间T1<T2<……<Tn
                 session1                   session2
T1         select count(*) from t;
           --显示结果(1000)条
T2         delete from t where rownum <=100;
T3                                          begin
                                             delete from t where rownum 
                                              <=100;  
                                              commit;
                                            end;
                                            /
T4         truncate table t;
T5         select count(*) from t;
           --这里显示的结果是多少(      )A:  1000        B:   900     C:   800     D:   0

Answer 1

这么快~~~~
truncate 是不是不需要commit？

Answer 2

这是在干嘛
truncate后不可能还有数据吧

Answer 3

truncate是dDl操作不需要commit
delete是dml操作需要commit