如何通过BBED找回删除数据
项目案例：客户删除delete了重要数据，无备份，客户联系我，要求恢复相应数据。本次通过实验方式重现客户现场。备份高于一切，首先备份，再操作
创建表格：
create table king(age number,name varchar2(20));
insert into king values(20,'rick');
insert into king values(30,'wuzy');
commit;
select dbms_rowid.rowid_relative_fno(rowid) rel_fno,dbms_rowid.rowid_block_number(rowid) blockno from king
4 303
delete from king where age=30;
commit
结果：
bbed恢复(建议关闭数据库）：
set file 4,303
find /c wuzy
File: /u01/app/oracle/oradata/orcl/users01.dbf (4)
Block: 303 Offsets: 8173 to 8191 Dba:0x0100012f
------------------------------------------------------------------------
77757a79 2c000202 c1150472 69636b01 064a2f
p kdbr
BBED> p kdbr
sb2 kdbr[0] @118 8077
sb2 kdbr[1] @120 8066
BBED> p *kdbr[0]
rowdata[11]
-----------
ub1 rowdata[11] @8177 0x2c
BBED> p *kdbr[1]
rowdata[0]
----------
ub1 rowdata[0] @8166 0x2c
BBED> set dba 4,303 offset 8173
DBA 0x0100012f (16777519 4,303)
OFFSET 8173
BBED> d /v dba 4,303 offset 8173
File: /u01/app/oracle/oradata/orcl/users01.dbf (4)
Block: 303 Offsets: 8173 to 8191 Dba:0x0100012f
-------------------------------------------------------
77757a79 2c000202 c1150472 69636b01 l wuzy,....rick.
06c42f l .
<16 bytes per line>
BBED> d /v offset 8166
File: /u01/app/oracle/oradata/orcl/users01.dbf (4)
Block: 303 Offsets: 8166 to 8191 Dba:0x0100012f
-------------------------------------------------------
3c020202 c11f0477 757a792c 000202c1 l <....wuzy,...
15047269 636b0106 c42f l ..rick..
<16 bytes per line>
BBED> modify /x 2c
File: /u01/app/oracle/oradata/orcl/users01.dbf (4)
Block: 303 Offsets: 8166 to 8191 Dba:0x0100012f
------------------------------------------------------------------------
2c020202 c11f0477 757a792c 000202c1 15047269 636b0106 c42f
<32 bytes per line>
BBED> sum apply
Check value for File 4, Block 303:
current = 0x6436, required = 0x6436
结果：
删减数据已经恢复。
注意：3C是已经删除的数据 2C是没有删除数据