生成测试表
conn liang/chengce243
create table tab_01(id int,name VARCHAR2(128));
insert into tab_01
select OBJECT_ID,OBJECT_NAME
from dba_objects where rownum<=10000;
commit;
create table tab_02 as select * from tab_01;
drop table tab_02 purge;
恢复的步骤为：
1.OFFLINE表所在的表空间
2.使用logminer从日志里面挖掘被drop掉的表其data object id。
3.扫描数据：scan extent
4.如果没有表结构信息，需要自动来判断：unload object data_object_id sample
5.恢复表：unload object data_object_id column coltype coltype...
6.ONLINE表所在的表空间
先将测试表所在的users表空间offline：
alter tablespace users offline;
使用logminer来查找被drop表的data object id：
select group#,status from v$log;
col member for a50
select member from v$logfile where group#=2;
MEMBER
--------------------------------------------------
/u01/oradata/orcl/redo02.log
exec sys.dbms_logmnr.add_logfile(logfilename=>'/u01/oradata/orcl/redo02.log');
exec sys.dbms_logmnr.start_logmnr(options=>sys.dbms_logmnr.dict_from_online_catalog);
set pagesize 999
set linesize 160
col scn for 999999999
col timestamp for a30
col sql_redo for a60
ALTER session SET nls_date_format='yyyy-mm-dd hh24:mi:ss';
select scn,timestamp,sql_redo from v$logmnr_contents where operation='DDL' and sql_redo like '%tab_02%' order by 2 ;
SCN TIMESTAMP SQL_REDO
---------- ------------------------------ ------------------------------------------------------------
976977 2019-03-07 16:26:59 create table tab_02 as select * from tab_01;
977005 2019-03-07 16:27:00 drop table tab_02 purge;
select scn,timestamp,sql_redo from v$logmnr_contents where timestamp=to_date('2019-03-07 16:27:00','yyyy-mm-dd hh24:mi:ss') order by 1;
SCN TIMESTAMP SQL_REDO
---------- ------------------------------ ------------------------------------------------------------
977001 2019-03-07 16:27:00 set transaction read write;
977001 2019-03-07 16:27:00 /* No SQL_REDO for temporary tables */
977002 2019-03-07 16:27:00 commit;
977004 2019-03-07 16:27:00 set transaction read write;
977004 2019-03-07 16:27:00
977005 2019-03-07 16:27:00 drop table tab_02 purge;
977008 2019-03-07 16:27:00 /* No SQL_REDO for temporary tables */
977008 2019-03-07 16:27:00 Unsupported
977009 2019-03-07 16:27:00
977009 2019-03-07 16:27:00
977009 2019-03-07 16:27:00
977009 2019-03-07 16:27:00 Unsupported
977009 2019-03-07 16:27:00
977009 2019-03-07 16:27:00
977009 2019-03-07 16:27:00
977010 2019-03-07 16:27:00 Unsupported
977010 2019-03-07 16:27:00 delete from "SYS"."OBJ$" where "OBJ#" = '87360' and "DATAOBJ
#" = '87360' and "OWNER#" = '84' and "NAME" = 'TAB_02' and "
NAMESPACE" = '1' and "SUBNAME" IS NULL and "TYPE#" = '2' and
"CTIME" = TO_DATE('2019-03-07 16:26:59', 'yyyy-mm-dd hh24:m
i:ss') and "MTIME" = TO_DATE('2019-03-07 16:26:59', 'yyyy-mm
-dd hh24:mi:ss') and "STIME" = TO_DATE('2019-03-07 16:26:59'
, 'yyyy-mm-dd hh24:mi:ss') and "STATUS" = '1' and "REMOTEOWN
ER" IS NULL and "LINKNAME" IS NULL and "FLAGS" = '0' and "OI
D$" IS NULL and "SPARE1" = '6' and "SPARE2" = '1' and "SPARE
3" = '84' and "SPARE4" IS NULL and "SPARE5" IS NULL and "SPA
RE6" IS NULL and ROWID = 'AAAAASAABAAAVCnAAa';
977011 2019-03-07 16:27:00
977011 2019-03-07 16:27:00
977011 2019-03-07 16:27:00
977011 2019-03-07 16:27:00
977012 2019-03-07 16:27:00 Unsupported
977012 2019-03-07 16:27:00 Unsupported
977013 2019-03-07 16:27:00 commit;
977016 2019-03-07 16:27:00 set transaction read write;
977016 2019-03-07 16:27:00 Unsupported
977016 2019-03-07 16:27:00 Unsupported
977017 2019-03-07 16:27:00 commit;
977017 2019-03-07 16:27:00 set transaction read write;
977017 2019-03-07 16:27:00
977020 2019-03-07 16:27:00 Unsupported
977021 2019-03-07 16:27:00 commit;
从SCN为977010的几行中，delete from "SYS"."OBJ$" where "OBJ#" = '87360' and "DATAOBJ#" = '87360' and "OWNER#" = '84' 可以看到被drop表的data object id为87360。
set linesize 180
col FILE_NAME for a50
col VALUE for a8
select ts#,file_id fno#,file_id rfno#,file_name,value
from V$tablespace t,dba_data_files d,v$parameter p
where t.name=d.tablespace_name
and p.name='db_block_size';
把查询结果贴到control.txt；
修改配置文件config.txt output_format 为 DMP
[oracle@hncdf odu]$ cat config.txt
byte_order little
block_size 8192
db_timezone -7
client_timezone 8
data_path data
charset_name ZHS16GBK
ncharset_name AL16UTF16
output_format DMP
lob_storage infile
clob_byte_order little
通过ODU的抽样来自动判断数据的类型：
ODU> scan extent tablespace 4;
scan extent start: 2019-03-07 16:45:46
scanning extent...
scanning extent finished.
scan extent completed: 2019-03-07 16:45:46
ODU> unload object 87360 sample
Unloading Object,object ID: 87360, Cluster: 0
output data is in file : 'data/ODU_0000087360.txt'
Sample result:
object id: 87360
tablespace no: 4
sampled 1022 rows
column count: 2
column 1 type: NUMBER
column 2 type: VARCHAR2
COMMAND:
unload object 87360 tablespace 4 column NUMBER VARCHAR2
ODU> unload object 87360 tablespace 4 column NUMBER VARCHAR2
Unloading Object,object ID: 87360, Cluster: 0
10000 rows unloaded
将测试表所在的users表空间online：
SQL> alter tablespace users online;
使用imp导入数据
imp liang/chengce243 file=data/ODU_0000087360.dmp fromuser=liang touser=liang
参考文档：http://www.laoxiong.net/category/odu