1. Oracle ASSM介绍
Oracle ASSM(Automatic Segment Space Managed)使用三级位图来管理数据库中的
空间,由于bbed工具不支持查询Segment Header的物理结构，造成Oracle dba无法深
入准确的查询位图结构及变化，本文借鉴bbed的展示方式，使用C语言完全解析
Oracle ASSM的三级位图结构，希望对各位有所帮助。解析结果如下所示，
2. 测试数据创建
create table hsql.test1(t1 char(10),t2 char(10)) tablespace test1;
insert into hsql.test1 values('1','a');
insert into hsql.test1 values('2','aa');
insert into hsql.test1 values('3','aaa');
insert into hsql.test1 values('4','aaaa');
insert into hsql.test1 values('5','aaaaa');
insert into hsql.test1 values('6','aaaaaa');
insert into hsql.test1 values('7','aaaaaaa');
insert into hsql.test1 values('8','aaaaaaaa');
insert into hsql.test1 values('9','aaaaaaaaa');
insert into hsql.test1 values('10','aaaaaaaaaa');
commit;
select * from hsql.test1;
begin
for i in 1..10000 loop
insert into hsql.test1 values(i,'a'||i);
commit;
end loop;
end;
/
3. unload 导出业务数据
[oracle@sourcedb xdul]$ ./xdul
xdul: Data Unload for Oracle version 1.1.1
Copyright(c) 2020 orastar.All rights reserved.
Wechat: xidoublestr
Email: 634025070@qq.com
loading default config.......
load config file 'config.txt' successful
loading default control file ......
ts# fn rfn bsize blocks filename
---- ---- ---- ----- -------- --------------------------------------------
0 1 1 8192 97280 /oradata/epmsn/system01.dbf
1 2 2 8192 89600 /oradata/epmsn/sysaux01.dbf
2 3 3 8192 8960 /oradata/epmsn/undotbs01.dbf
4 4 4 8192 640 /oradata/epmsn/users01.dbf
6 5 5 8192 12800 /oradata/epmsn/test1.dbf
load control file 'control.txt' successful
XDUL>list user;
userid username
------ ----------
0 SYS
1 PUBLIC
2 CONNECT
3 RESOURCE
4 DBA
5 SYSTEM
6 SELECT_CATALOG_ROLE
7 EXECUTE_CATALOG_ROLE
8 DELETE_CATALOG_ROLE
9 OUTLN
10 EXP_FULL_DATABASE
11 IMP_FULL_DATABASE
12 LOGSTDBY_ADMINISTRATOR
13 DBFS_ROLE
14 DIP
15 AQ_ADMINISTRATOR_ROLE
16 AQ_USER_ROLE
17 DATAPUMP_EXP_FULL_DATABASE
18 DATAPUMP_IMP_FULL_DATABASE
19 ADM_PARALLEL_EXECUTE_TASK
20 GATHER_SYSTEM_STATISTICS
21 ORACLE_OCM
22 RECOVERY_CATALOG_OWNER
23 SCHEDULER_ADMIN
24 HS_ADMIN_SELECT_ROLE
25 HS_ADMIN_EXECUTE_ROLE
26 HS_ADMIN_ROLE
27 GLOBAL_AQ_USER_ROLE
28 OEM_ADVISOR
29 OEM_MONITOR
30 DBSNMP
31 APPQOSSYS
32 WMSYS
33 WM_ADMIN_ROLE
34 JAVAUSERPRIV
35 JAVAIDPRIV
36 JAVASYSPRIV
37 JAVADEBUGPRIV
38 EJBCLIENT
39 JMXSERVER
40 JAVA_ADMIN
41 JAVA_DEPLOY
42 EXFSYS
43 CTXSYS
44 CTXAPP
45 XDB
46 ANONYMOUS
47 XDBADMIN
48 XDB_SET_INVOKER
49 AUTHENTICATEDUSER
50 XDB_WEBSERVICES
51 XDB_WEBSERVICES_WITH_PUBLIC
52 XDB_WEBSERVICES_OVER_HTTP
53 ORDSYS
54 ORDDATA
55 ORDPLUGINS
56 SI_INFORMTN_SCHEMA
2147483638 XS$NULL
57 MDSYS
58 ORDADMIN
59 OLAP_XS_ADMIN
60 OLAPSYS
61 OLAP_DBA
62 CWM_USER
63 OLAP_USER
64 MDDATA
65 SPATIAL_WFS_ADMIN
66 SPATIAL_WFS_ADMIN_USR
67 WFS_USR_ROLE
68 SPATIAL_CSW_ADMIN
69 SPATIAL_CSW_ADMIN_USR
70 CSW_USR_ROLE
71 SYSMAN
72 MGMT_USER
73 MGMT_VIEW
74 FLOWS_FILES
75 APEX_PUBLIC_USER
76 APEX_ADMINISTRATOR_ROLE
77 APEX_030200
78 OWBSYS
79 OWBSYS_AUDIT
80 OWB$CLIENT
81 OWB_DESIGNCENTER_VIEW
82 OWB_USER
83 SCOTT
84 HSQL
85 _NEXT_USER
XDUL>set user;
input username: HSQL
cur_user: HSQL,cur_userid:84
XDUL>XDUL>
XDUL>list table;
OBJ#,DATAOBJ#,OWNER#,NAME,SUBNAME,ROWCNT,BLKCNT
------------------------------------------------------------
88135,88135,84,TEST1,,10,5
88141,88142,84,TEST_DATE,,11,5
XDUL>desc
input OBJ#: 88135
Name,Type
----------------------
T1,char(10)
T2,char(10)
XDUL>XDUL>unload table;
input OBJ#: 88135
Unloading table: HSQL.TEST1,object ID: 88135
Unloading segment,storage(Obj#=88135 DataObj#=88135 TS#=6 File#=5 Block#=138 Cluster=0) --说明段头块为 File#=5 Block#=138
10010 rows unloaded
XDUL>
4. 格式化解析L3 BMB
XDUL>bmb
input fno: 5
input blk: 138
struct kcbh, 20 bytes @0
ub1 type_kcbh @0 0x23
ub1 frmt_kcbh @1 0xa2
ub1 spare1_kcbh @2 0x00
ub1 spare2_kcbh @3 0x00
ub4 rdba_kcbh @4 0x0140008a
ub4 bas_kcbh @8 0x002508bc
ub2 wrp_kcbh @12 0x0000
ub1 seq_kcbh @14 0x03
ub1 flg_kcbh @15 0x04
ub2 chkval_kcbh @16 0xf230
ub2 spare3_kcbh @18 0x0000
struct ech(Extent Control Header) @36
ub4 extents_ech @36 0x00000006
ub4 blocks_ech @40 0x00000030
ub4 offset_ech @44 0x00000a9c
ub4 ext_ech @48 0x00000005
ub4 blk_ech @52 0x00000008
ub4 extsize_ech @56 0x00000008
ub4 hw_ech @60 0x014000b8
ub4 hwmapblk_ech @64 0x00000000
ub4 hwoffset_ech @68 0x00000005
ub4 hwblocksshf_ech @72 0x00000000
ub4 hwblksbelow_ech @76 0x0000002b
ub4 lhwmext_ech @92 0x00000005
ub4 lhwmblk_ech @96 0x00000008
ub4 lhwmextsize_ech @100 0x00000008
ub4 lhwm_ech @104 0x014000b8
ub4 lhwmapblk_ech @108 0x00000000
ub4 lhwoffset_ech @112 0x00000005
ub4 lhwblocksshf_ech @116 0x00000000
ub4 lhwblksbelow_ech @120 0x0000002b
ub4 segtype_ech @208 0x00000001
ub4 blksz_ech @212 0x00002000
ub4 fbsz_echo @216 0x00000000
ub4 l2asoffset_ech @220 0x00001434
ub4 firstbmb3_echo @224 0x00000000
ub4 l2hfinsert_ech @228 0x01400089
ub4 nl2_echo @232 0x00000001
ub4 lastBMB1_echo @236 0x014000a8
ub4 lastBMB2_echo @240 0x01400089
ub4 lastBMB3_echo @244 0x00000000
ub4 mhnext_echo @260 0x00000000
ub4 mhext_echo @264 0x00000006
ub4 mhobj_ech @272 0x00015847
ub4 mhflag_ech @276 0x10000000
struct em(Extent Map) @280
ub4 dba_em[0] @280 0x01400088
ub4 len_em[0] @284 0x00000008
ub4 dba_em[1] @288 0x01400080
ub4 len_em[1] @292 0x00000008
ub4 dba_em[2] @296 0x01400098
ub4 len_em[2] @300 0x00000008
ub4 dba_em[3] @304 0x014000a0
ub4 len_em[3] @308 0x00000008
ub4 dba_em[4] @312 0x014000a8
ub4 len_em[4] @316 0x00000008
ub4 dba_em[5] @320 0x014000b0
ub4 len_em[5] @324 0x00000008
struct am(Auxillary Map) @2736
ub4 fdba_am[0] @2736 0x01400088
ub4 datadba_am[0] @2740 0x0140008b
ub4 fdba_am[1] @2744 0x01400088
ub4 datadba_am[1] @2748 0x01400080
ub4 fdba_am[2] @2752 0x01400098
ub4 datadba_am[2] @2756 0x01400099
ub4 fdba_am[3] @2760 0x01400098
ub4 datadba_am[3] @2764 0x014000a0
ub4 fdba_am[4] @2768 0x014000a8
ub4 datadba_am[4] @2772 0x014000a9
ub4 fdba_am[5] @2776 0x014000a8
ub4 datadba_am[5] @2780 0x014000b0
ub4 slbbdba1_am @5192 0x01400089
ub4 tail_kcbh @8188 0x08bc2303
XDUL>
5. 格式化解析L2 BMB
XDUL>bmb
input fno: 5
input blk: 137
struct kcbh, 20 bytes @0
ub1 type_kcbh @0 0x21
ub1 frmt_kcbh @1 0xa2
ub1 spare1_kcbh @2 0x00
ub1 spare2_kcbh @3 0x00
ub4 rdba_kcbh @4 0x01400089
ub4 bas_kcbh @8 0x002508ba
ub2 wrp_kcbh @12 0x0000
ub1 seq_kcbh @14 0x02
ub1 flg_kcbh @15 0x04
ub2 chkval_kcbh @16 0xdebc
ub2 spare3_kcbh @18 0x0000
struct hc(Header Control) @76
ub4 pdba_hc @76 0x0140008a
ub4 number_hc @80 0x00000003
ub4 nfree_hc @84 0x00000001
ub4 ffree_hc @88 0x00000002
ub4 inc_hc @92 0x00000000
ub4 opcode_hc @96 0x00000000
ub4 objd_hc @104 0x00015847
struct bmb1array @116
ub4 dba_bmb1array[0] @116 0x01400088
ub4 free_bmb1array[0] @120 0x0001
ub4 inst_bmb1array[0] @122 0x0001
ub4 dba_bmb1array[1] @124 0x01400098
ub4 free_bmb1array[1] @128 0x0001
ub4 inst_bmb1array[1] @130 0x0001
ub4 dba_bmb1array[2] @132 0x014000a8
ub4 free_bmb1array[2] @136 0x0005
ub4 inst_bmb1array[2] @138 0x0001
ub4 tail_kcbh @8188 0x08ba2102
XDUL>XDUL>
XDUL>
6. 格式化解析L1 BMB
XDUL>
XDUL>bmb
input fno: 5
input blk: 136
struct kcbh, 20 bytes @0
ub1 type_kcbh @0 0x20
ub1 frmt_kcbh @1 0xa2
ub1 spare1_kcbh @2 0x00
ub1 spare2_kcbh @3 0x00
ub4 rdba_kcbh @4 0x01400088
ub4 bas_kcbh @8 0x0024daa8
ub2 wrp_kcbh @12 0x0000
ub1 seq_kcbh @14 0x02
ub1 flg_kcbh @15 0x04
ub2 chkval_kcbh @16 0xad46
ub2 spare3_kcbh @18 0x0000
struct hcbmb1(Header Control) @76
ub4 nbits_bmb1 @76 0x00000004
ub4 embo_bmb1 @80 0xffffffff
ub4 fub_bmb1 @88 0x00000003
ub4 total_bmb1 @92 0x00000010
ub2 nranges_bmb1 @96 0x0002
ub2 ownerins_bmb1 @98 0x0001
ub4 nf1_bmb1 @100 0x00000000
ub4 nf2_bmb1 @104 0x00000000
ub4 nf3_bmb1 @108 0x00000000
ub4 nf4_bmb1 @112 0x00000000
ub4 ffd_bmb1 @116 0x00000010
ub4 insowncha_bmb1 @120 0x5e875a85
ub4 lastsucsea_bmb1 @124 0x5e875a85
ub4 pdba_bmb1 @144 0x01400089
ub4 objd_bmb1 @192 0x00015847
ub4 deascnbas_bmb1 @196 0x00247325
ub2 deascnwap_bmb1 @200 0x0000
struct dbarange @116
ub4 dba_dbarange[0] @116 0x01400088
ub4 len_dbarange[0] @120 0x00000008
ub4 offset_dbarange[0] @124 0x00000000
ub4 dba_dbarange[1] @128 0x01400080
ub4 len_dbarange[1] @132 0x00000008
ub4 offset_dbarange[1] @136 0x00000008
ub4 tail_kcbh @8188 0xdaa82002
XDUL>
7. Segment Header Block Types
Decimal Hex Type
1 0x01 undo segment header
11 0x0b data file header
12 0x0c data segment header with FLG blocks
14 0x0e unlimited undo segment header
15 0x0f unlimited save undo segment header
16 0x10 unlimited data segment header
17 0x11 unlimited data segment header with FLG blocks
18 0x12 extent map block
23 0x17 bitmapped segment header
29 0x1d bitmapped file space header
32 0x20 first level bitmap block
33 0x21 second level bitmap block
34 0x22 third level bitmap block
35 0x23 Pagetable segment header block
36 0x24 Pagetable extent map block
37 0x25 System Managed Undo Extent Map Block
8. dump 段头块
alter session set tracefile_identifier='orastar_01';
oradebug setmypid
alter system dump datafile 5 block 138;
oradebug close_trace
oradebug tracefile_name
--dump Extent Map结果：
Extent Map
-----------------------------------------------------------------
0x01400088 length: 8
0x01400080 length: 8
0x01400098 length: 8
0x014000a0 length: 8
0x014000a8 length: 8
0x014000b0 length: 8
--手工解析 Extent Map结果：
struct em(Extent Map) @280
ub4 dba_em[0] @280 0x01400088
ub4 len_em[0] @284 0x00000008
ub4 dba_em[1] @288 0x01400080
ub4 len_em[1] @292 0x00000008
ub4 dba_em[2] @296 0x01400098
ub4 len_em[2] @300 0x00000008
ub4 dba_em[3] @304 0x014000a0
ub4 len_em[3] @308 0x00000008
ub4 dba_em[4] @312 0x014000a8
ub4 len_em[4] @316 0x00000008
ub4 dba_em[5] @320 0x014000b0
ub4 len_em[5] @324 0x00000008
通过对比Oracle dump结果与手工解析Extent Map结果一致。
文章转载自数据库技术笔记，如果涉嫌侵权，请发送邮件至：contact@modb.pro进行举报，并提供相关证据，一经查实，墨天轮将立刻删除相关内容。
