Flashback Query：查询过去某个时间点对象中保存的记录信息，在当前时间与指定过去某个时间点之间。
SQL> conn scott/oracle
Connected.
SQL> select dbms_flashback.get_system_change_number from dual;
GET_SYSTEM_CHANGE_NUMBER
------------------------
1196559
SQL> update flash_tbl set id=id+100 where id>15;
5 rows updated.
SQL> commit;
Commit complete.
SQL> delete flash_tbl where id<5;
4 rows deleted.
SQL> commit;
Commit complete.
SQL> desc flash_tbl
Name Null Type
----------------------------------------- -------- ----------------------------
ID NUMBER
VL VARCHAR2(1)
SQL> insert into flash_tbl values(300,'r');
1 row created.
SQL> insert into flash_tbl values(500,'t');
1 row created.
SQL> select dbms_flashback.get_system_change_number from dual;
GET_SYSTEM_CHANGE_NUMBER
------------------------
1196625
SQL> select id,vl,versions_startscn,versions_endscn,versions_operation,versions_xid from flash_tbl versions between scn 1196559 and 1196625;
ID V VERSIONS_STARTSCN VERSIONS_ENDSCN V VERSIONS_XID
---------- - ----------------- --------------- - ----------------
120 S 1196576 U 0700290074010000
119 R 1196576 U 0700290074010000
118 Q 1196576 U 0700290074010000
117 P 1196576 U 0700290074010000
116 O 1196576 U 0700290074010000
10 I
11 J
12 K
13 L
14 M
15 N
ID V VERSIONS_STARTSCN VERSIONS_ENDSCN V VERSIONS_XID
---------- - ----------------- --------------- - ----------------
16 O 1196576
17 P 1196576
18 Q 1196576
19 R 1196576
20 S 1196576
4 C 1196588 D 08000B0096010000
3 B 1196588 D 08000B0096010000
2 A 1196588 D 08000B0096010000
1 / 1196588 D 08000B0096010000
1 / 1196588
2 A 1196588
ID V VERSIONS_STARTSCN VERSIONS_ENDSCN V VERSIONS_XID
---------- - ----------------- --------------- - ----------------
3 B 1196588
4 C 1196588
5 D
6 E
7 F
8 G
9 H
29 rows selected.
根据记录，可以看到开始SCN和结束SCN，从操作列有I（插入），U（更新），D（删除），还有事务ID。
SQL> select dbms_flashback.get_system_change_number from dual;
GET_SYSTEM_CHANGE_NUMBER
------------------------
1200548
SQL> delete flash_tbl where id=116;
1 row deleted.
SQL> commit;
Commit complete.
SQL> select dbms_flashback.get_system_change_number from dual;
GET_SYSTEM_CHANGE_NUMBER
------------------------
1200555
SQL> conn / as sysdba
Connected.
SQL> grant select any transaction to scott;
Grant succeeded.
SQL> conn scott/oracle
Connected.
SQL> select xid,commit_scn,commit_timestamp,operation,undo_sql from flashback_transaction_query Q where Q.xid in(select versions_xid from flash_tbl versions between
scn 1200548 and 1200555);
XID COMMIT_SCN COMMIT_TI OPERATION
---------------- ---------- --------- --------------------------------
UNDO_SQL
--------------------------------------------------------------------------------
0A002F0062010000 1200554 31-MAR-14 DELETE
insert into "SCOTT"."FLASH_TBL"("ID","VL") values ('116','O');
0A002F0062010000 1200554 31-MAR-14 BEGIN
通过上面可以看到，刚才所做的操作及时间，与LogMiner功能挺像。