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Oracle10g Flashback Query数据闪回
Oracle 当闪回事务处理查询与闪回版本查询同时使用时，我们可以轻易地从用户或者应用程序错误恢复。 以下是闪回版本查询的示例: 1.执行DML操作 EYGLE on 30-MAR-05 >create table t as select username,user_id from dba_users; Table created. EYGLE on 30-MAR-05 >select * from t; USERNAME USER_ID ------------------------------ ---------- SYSTEM 5 SYS 0 TEST 25 EYGLE 26 SCOTT 29 DIP 19 TRANS 27 TEST1 28 OPERATOR 31 WMSYS 23 DBSNMP 22 USERNAME USER_ID ------------------------------ ---------- OUTLN 11 12 rows selected. EYGLE on 30-MAR-05 >delete from t where username='OUTLN'; 1 row deleted. EYGLE on 30-MAR-05 >commit; Commit complete. EYGLE on 30-MAR-05 >delete from t where username='TEST1'; 1 row deleted. EYGLE on 30-MAR-05 >commit; Commit complete. EYGLE on 30-MAR-05 >select * from t; USERNAME USER_ID ------------------------------ ---------- SYSTEM 5 SYS 0 TEST 25 EYGLE 26 SCOTT 29 DIP 19 TRANS 27 OPERATOR 31 WMSYS 23 DBSNMP 22 10 rows selected. EYGLE on 30-MAR-05 >update t set user_id=1 where username='EYGLE'; 1 row updated. EYGLE on 30-MAR-05 >commit; Commit complete. EYGLE on 30-MAR-05 >delete from t where user_id >10; 7 rows deleted. EYGLE on 30-MAR-05 >commit; Commit complete. EYGLE on 30-MAR-05 >select * from t; USERNAME USER_ID ------------------------------ ---------- SYSTEM 5 SYS 0 EYGLE 1 EYGLE on 30-MAR-05 >insert into t values('PENNY',2); 1 row created. EYGLE on 30-MAR-05 >commit; Commit complete. 2.执行闪回版本查询 EYGLE on 30-MAR-05 >select versions_starttime, versions_endtime, versions_xid, 2 versions_operation, username,user_id 3 from t versions between timestamp minvalue and maxvalue 4 / VERSIONS_STARTTIME VERSIONS_ENDTIME VERSIONS_XID V USERNAME USER_ID ------------------------------ ------------------------------ ---------------- - ---------- ---------- 30-MAR-05 09.34.49 AM 000A000B000000F1 D DBSNMP 22 30-MAR-05 09.34.49 AM 000A000B000000F1 D WMSYS 23 30-MAR-05 09.34.49 AM 000A000B000000F1 D OPERATOR 31 30-MAR-05 09.34.49 AM 000A000B000000F1 D TRANS 27 30-MAR-05 09.34.49 AM 000A000B000000F1 D DIP 19 30-MAR-05 09.34.49 AM 000A000B000000F1 D SCOTT 29 30-MAR-05 09.34.49 AM 000A000B000000F1 D TEST 25 30-MAR-05 09.34.15 AM 0001001900000F0F U EYGLE 1 30-MAR-05 09.33.51 AM 00080016000000EF D TEST1 28 30-MAR-05 09.33.23 AM 0004000A000005EF D OUTLN 11 SYSTEM 5 VERSIONS_STARTTIME VERSIONS_ENDTIME VERSIONS_XID V USERNAME USER_ID ------------------------------ ------------------------------ ---------------- - ---------- ---------- SYS 0 30-MAR-05 09.34.49 AM TEST 25 30-MAR-05 09.34.15 AM EYGLE 26 30-MAR-05 09.34.49 AM SCOTT 29 30-MAR-05 09.34.49 AM DIP 19 30-MAR-05 09.34.49 AM TRANS 27 30-MAR-05 09.33.51 AM TEST1 28 30-MAR-05 09.34.49 AM OPERATOR 31 30-MAR-05 09.34.49 AM WMSYS 23 30-MAR-05 09.34.49 AM DBSNMP 22 30-MAR-05 09.33.23 AM OUTLN 11 VERSIONS_STARTTIME VERSIONS_ENDTIME VERSIONS_XID V USERNAME USER_ID ------------------------------ ------------------------------ ---------------- - ---------- ---------- 30-MAR-05 09.49.24 AM 00080006000000EF I PENNY 2 23 rows selected. EYGLE on 30-MAR-05 > 我们可以看到，以上事务的时间以及数据更改。
