truncate恢复方法集合
作者：互联网
truncate操作是比较危险的操作，不记录redo，不能通过闪回查询来找回数据，但是只要段所占用的块没有全部被重新占用的情况下，我们还是可以通过一些特殊的办法来找回truncate掉的数据，因为当Truncate命令发起之后，Oracle实际上并没有在删除底层数据块上的数据，而是要等到重用的时候才会把这一部分数据回收，于是这给了我们一个能够恢复数据库的机会。
总体而言，恢复的办法是通过一些大牛写的工具来恢复，分为收费和免费的，我们下边分别说明。实验部分我们只实验fy_recover_data包和gdul工具。
2 免费软件
2.1 fy_recover_data包
作者个人信息：
WWW.HelloDBA.COM
Created By: Fuyuncat
Created Date: 08/08/2012
Email: Fuyuncat@gmail.com
Copyright (c), 2014, WWW.HelloDBA.COM All rights reserved.
Latest Version: http://www.HelloDBA.com/download/FY_Recover_Data.zip
该包采用纯plsql语句恢复被truncate掉的表，操作比较简单，下载可以去官网下载，或者小麦苗的云盘共享目录。
1.1 gdul工具
GDUL是老耿开发的一款类dul工具，当数据库由于某种原因无法打开时，可以利用GDUL把表数据直接读取出来，工具下载地址参考小麦苗的blog，老耿的信息如下：
*********************************************************************
GDUL for ORACLE DB.
Version 4.0.0.1, build date: 2016.04.12.
Copyright (c) 2007, 2016. Andy Geng. ALL RIGHTS RESERVED.
Email: dbtool@aliyun.com
WeChat official account: dbtool
QQ group: 235019291
1 实验环境介绍
项目 | db |
db 类型 | 单实例 |
db version | 11.2.0.4.0 |
db 存储 | FS |
主机IP地址/hosts配置 | 192.168.59.129 |
OS版本及kernel版本 | AIX 7.1 64位 |
归档模式 | Archive Mode |
ORACLE_SID | oralhr |
2 实验目标
将truncate掉的表数据成功找回。
3 实验过程
一.3.1 fy_recover_data包恢复truncate的表
[ZFXDESKDB1:oracle]:/oracle>ORACLE_SID=oraESKDB1
[ZFXDESKDB1:oracle]:/oracle>sqlplus / as sysdba
SQL*Plus: Release 11.2.0.4.0 Production on Mon Mar 21 15:51:55 2016
Copyright (c) 1982, 2013, Oracle. All rights reserved.
Connected to:
Oracle Database 11g Enterprise Edition Release 11.2.0.4.0 - 64bit Production
With the Partitioning, Real Application Clusters, Automatic Storage Management, OLAP,
Data Mining and Real Application Testing options
SYS@oraESKDB1> set time on;
15:52:10 SYS@oraESKDB1> set timing on;
15:52:10 SYS@oraESKDB1> set serveroutput on;
15:52:10 SYS@oraESKDB1> create table scott.TB_0321 as SELECT * FROM dba_objects;
Table created.
Elapsed: 00:00:00.59
15:52:18 SYS@oraESKDB1> SELECT COUNT(1) FROM scott.TB_0321;
COUNT(1)
----------
86651
Elapsed: 00:00:00.19
15:52:24 SYS@oraESKDB1> INSERT INTO scott.TB_0321 SELECT * FROM scott.TB_0321;
86651 rows created.
Elapsed: 00:00:00.26
15:52:30 SYS@oraESKDB1> COMMIT;
Commit complete.
Elapsed: 00:00:00.01
15:52:30 SYS@oraESKDB1> INSERT INTO scott.TB_0321 SELECT * FROM scott.TB_0321;
COMMIT;
173302 rows created.
Elapsed: 00:00:00.43
15:53:02 SYS@oraESKDB1> SELECT COUNT(1) FROM scott.TB_0321;
COUNT(1)
----------
346604
Elapsed: 00:00:00.27
16:15:18 SYS@oraESKDB1> SELECT d.BYTES/1024/1024 FROM dba_segments d WHERE d.segment_name ='TB_0321';
D.BYTES/1024/1024
-----------------
40
Elapsed: 00:00:00.44
16:15:25 SYS@oraESKDB1> truncate table scott.TB_0321;
Table truncated.
Elapsed: 00:00:00.20
16:15:46 SYS@oraESKDB1> SELECT COUNT(1) FROM scott.TB_0321;
COUNT(1)
----------
0
Elapsed: 00:00:00.01
====》数据已经被truncate掉了，下边我们来恢复
16:15:52 SYS@oraESKDB1> @/oracle/FY_Recover_Data.pck
Package created.
Elapsed: 00:00:00.06
Package body created.
Elapsed: 00:00:00.03
16:15:59 SYS@oraESKDB1> exec fy_recover_data.recover_truncated_table('scott','TB_0321');
16:16:06: Use existing Directory Name: FY_DATA_DIR
16:16:07: Recover Table: SCOTT.TB_0321$
16:16:09: Restore Table: SCOTT.TB_0321$$
16:16:24: Copy file of Recover Tablespace: FY_REC_DATA_COPY.DAT1
16:16:24: begin to recover table SCOTT.TB_0321
16:16:24: Use existing Directory Name: TMP_HF_DIR
16:17:09: Recovering data in datafile +DATA/oraeskdb/datafile/users.351.902678817
16:17:09: Use existing Directory Name: TMP_HF_DIR
16:39:16: 4984 truncated data blocks found.
16:39:16: 346604 records recovered in backup table SCOTT.TB_0321$$
16:39:17: Total: 4984 truncated data blocks found.
16:39:17: Total: 346604 records recovered in backup table SCOTT.TB_0321$$
16:39:17: Recovery completed.
16:39:17: Data has been recovered to SCOTT.TB_0321$$
PL/SQL procedure successfully completed.
Elapsed: 00:23:11.59
16:39:17 SYS@oraESKDB1> SELECT COUNT(1) FROM scott.TB_0321$$;
COUNT(1)
----------
346604
Elapsed: 00:00:01.55
16:40:51 SYS@oraESKDB1>
16:40:51 SYS@oraESKDB1> alter table scott.TB_0321 nologging;
Table altered.
Elapsed: 00:00:00.03
16:41:43 SYS@oraESKDB1> insert /*+append*/ into scott.TB_0321 select * from scott.TB_0321$$;
346604 rows created.
Elapsed: 00:00:00.86
16:41:52 SYS@oraESKDB1> commit;
Commit complete.
Elapsed: 00:00:00.01
16:41:55 SYS@oraESKDB1> alter table scott.TB_0321 logging;
Table altered.
Elapsed: 00:00:00.02
16:42:06 SYS@oraESKDB1>
16:42:06 SYS@oraESKDB1> drop tablespace FY_REC_DATA including contents and datafiles;
Tablespace dropped.
Elapsed: 00:00:08.00
16:42:35 SYS@oraESKDB1> drop tablespace FY_RST_DATA including contents and datafiles;
Tablespace dropped.
Elapsed: 00:00:07.59
16:42:44 SYS@oraESKDB1>
数据成功恢复。
标签：00,0321,truncate,恢复,Elapsed,SYS,集合,TB,oraESKDB1 来源： https://blog.51cto.com/lhrbest/2713526