场景1
表t3
SQL> select * from t3;
ID NAME
1 aaa
2 bbbb
SQL> update t3 set name='cccc' where name='bbbb'; ###这里更新值长度相同 1 row updated.
SQL> commit;
Commit complete.
SQL> alter system flush buffer_cache;
System altered.
BBED> set file 5 block 2207
FILE# 5
BLOCK# 2207
BBED> dump /v offset 8000 count 200
File: /u01/app/oracle/oradata/orcl/test01.dbf (5)
46004700 48004900 4a004b00 4c004d00 l F.G.H.I.J.K.L.M.
4e004f00 50005100 52005300 54005500 l N.O.P.Q.R.S.T.U.
56005700 58005900 5a005b00 5c005d00 l V.W.X.Y.Z.[.\.].
5e005f00 60006100 62006300 64006500 l ^._.`.a.b.c.d.e.
66006700 68006900 6a006b00 6c006d00 l f.g.h.i.j.k.l.m.
6e006f00 70007100 72007300 74007500 l n.o.p.q.r.s.t.u.
76007700 78007900 7a007b00 7c007d00 l v.w.x.y.z.{.|.}.
7e007f00 80008100 82008300 84008500 l ~……………
86008700 88008900 8a008b00 8c008d00 l …………….
8e008f00 90009100 92009300 94009500 l …………….
96009700 9800902c 020202c1 03046363 l …….,..cc
63632c00 0202c102 03616161 0106c52c l cc,…aaa..ì ####把bbbb的值更新为cccc
2c1030463636363---cccc
2c10203616161--aaa
BBED> p kdbr
sb2 kdbr[] @118 8078
sb2 kdbr[] @120 8067
BBED> p *kdbr[]
ub1 rowdata[] @8167 0x2c
BBED> x/rncccccc
flag@8167: 0x2c (KDRHFL, KDRHFF, KDRHFH)
lock@8168: 0x02
cols@8169: 2
col 0[] @8170: 2
col 1[] @8173: cccc ####把bbbb的值更新为cccc
更新前后值的长度相同,在原位置进行更新
例2 修改值之后的长度大于之前的值长度
SQL> select * from t3;
ID NAME
1 aaa
2 cccc
SQL> update t3 set name='dddddd' where name='cccc'; ###更新的值的长度变长
1 row updated.
SQL> commit;
Commit complete.
SQL> alter system flush buffer_cache;
System altered.
BBED> set file 5 block 2207
FILE# 5
BLOCK# 2207
BBED> p kdbr
sb2 kdbr[] @118 8078
sb2 kdbr[] @120 8054
BBED> p *kdbr[]
ub1 rowdata[] @8154 0x2c
BBED> x/rncccccc
flag@8154: 0x2c (KDRHFL, KDRHFF, KDRHFH)
lock@8155: 0x01
cols@8156: 2
col 0[] @8157: 2 ###id=2
col 1[] @8160: dddddd ##值更新为dddddd
BBED> dump /v offset 8000 count 200
File: /u01/app/oracle/oradata/orcl/test01.dbf (5)
46004700 48004900 4a004b00 4c004d00 l F.G.H.I.J.K.L.M.
4e004f00 50005100 52005300 54005500 l N.O.P.Q.R.S.T.U.
56005700 58005900 5a005b00 5c005d00 l V.W.X.Y.Z.[.\.].
5e005f00 60006100 62006300 64006500 l ^._.`.a.b.c.d.e.
66006700 68006900 6a006b00 6c006d00 l f.g.h.i.j.k.l.m.
6e006f00 70007100 72007300 74007500 l n.o.p.q.r.s.t.u.
76007700 78007900 7a007b00 7c007d00 l v.w.x.y.z.{.|.}.
7e007f00 80008100 82008300 84008500 l ~……………
86008700 88008900 8a008b00 8c008d00 l …………….
8e008f00 90009100 92002c01 0202c103 l ……….,..
06646464 6464642c 000202c1 03046363 l .dddddd,…cc ###这里cccc的值还在,新的值dddddd放在后面的位置
63632c00 0202c102 03616161 0106462d l cc,…aaa..F-
<16 bytes per line>
SQL> select dump('d','') from dual;
Typ=96 Len=1: 64
SQL> select * from t3;
ID NAME
1 aaa
2 dddddd
2c10306646464646464---dddddd ###新增加记录
2c1030463636363---cccc ###修改之后,这个值没变
2c10203616161 ---aaa
测试通过bbed把dddddd的值修改回ccccc,而不使用update命令
原来cccc的位置
SQL> select to_char(8067,'xxxxxxxxxxxxxx') from dual;
1f83
SQL> select to_char(8054,'xxxxxxxxxx') from dual;
1f76
新值dddddd的位置 76,修改为旧值cccc位置83
BBED> modify /x 83 offset 120
Warning: contents of previous BIFILE will be lost. Proceed? (Y/N) y
File: /u01/app/oracle/oradata/orcl/test01.dbf (5)
831f0000 00000000 00000000 00000000 00000000 00000000 00000000 00000000
00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000
00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000
00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000
00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000
00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000
00000000 00000000
<32 bytes per line>
BBED> sum apply
Check value for File 5, Block 2207:
current = 0x2191, required = 0x2191
修改事务槽
BBED> dump /v offset 8168
File: /u01/app/oracle/oradata/orcl/test01.dbf (5)
000202c1 03046363 63632c00 0202c102 l …cccc,.. ####cccc事务槽位00
03616161 0106462d l .aaa..F-
<16 bytes per line>
BBED> dump /v offset 8155
File: /u01/app/oracle/oradata/orcl/test01.dbf (5)
010202c1 03066464 64646464 2c000202 l …dddddd,… ####dddddd事务槽的值为01
c1030463 6363632c 000202c1 02036161 l.cccc,…aa
61010646 2d l a..F-
<16 bytes per line>
BBED> modify /x 00 offset 8155 ##修改dddddd事务槽为00
File: /u01/app/oracle/oradata/orcl/test01.dbf (5)
000202c1 03066464 64646464 2c000202 c1030463 6363632c 000202c1 02036161
61010646 2d
<32 bytes per line>
BBED> sum apply
Check value for File 5, Block 2207:
current = 0x2091, required = 0x2091
BBED> modify /x 01 offset 8168 ##修改cccc事务槽为01
File: /u01/app/oracle/oradata/orcl/test01.dbf (5)
010202c1 03046363 63632c00 0202c102 03616161 0106462d
<32 bytes per line>
BBED> sum apply
Check value for File 5, Block 2207:
current = 0x2090, required = 0x2090
有效空间设置(这一块的值和位置没有搞明白)
BBED> modify /x 5c offset 110
File: /u01/app/oracle/oradata/orcl/test01.dbf (5)
5c1f6b1f 00000200 8e1f831f 00000000 00000000 00000000 00000000 00000000
00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000
00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000
00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000
00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000
00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000
00000000 00000000
<32 bytes per line>
BBED> modify /x 5c offset 112
File: /u01/app/oracle/oradata/orcl/test01.dbf (5)
5c1f0000 02008e1f 831f0000 00000000 00000000 00000000 00000000 00000000
00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000
00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000
00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000
00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000
00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000
00000000 00000000
<32 bytes per line>
BBED> sum apply
Check value for File 5, Block 2207:
current = 0x2090, required = 0x2090
BBED> verify
DBVERIFY - Verification starting
FILE = /u01/app/oracle/oradata/orcl/test01.dbf
BLOCK = 2207
Block Checking: DBA = 20973727, Block Type = KTB-managed data block
data header at 0x7f7c53a15264
kdbchk: the amount of space used is not equal to block size
used=43 fsc=0 avsp=8028 dtl=8088
Block 2207 failed with check code 6110
DBVERIFY - Verification complete
Total Blocks Examined : 1
Total Blocks Processed (Data) : 1
Total Blocks Failing (Data) : 1
Total Blocks Processed (Index): 0
Total Blocks Failing (Index): 0
Total Blocks Empty : 0
Total Blocks Marked Corrupt : 0
Total Blocks Influx : 0
Message 531 not found; product=RDBMS; facility=BBED
SQL> alter system flush buffer_cache;
System altered.
SQL> select * from t3; ##没有使用update命令,只用bbed把dddddd的值修改回cccc
ID NAME
1 aaa
2 cccc
手机扫一扫
移动阅读更方便
你可能感兴趣的文章