一、概念介绍
Oracle数据库中bootstrap是一组表，告诉我们其余的表在哪里。类似于数据字典的数据字典。它位于一个固定的位置--如磁盘驱动器上的“引导记录”。我们总能在一个已知的地点找到它。--by Tom Kyte
通常，Bootstrap是一种将计算机程序的前几条指令加载到活动内存中，然后使用它们来加载程序的其余部分的技术,在Oracle中，Bootstrap指的是在打开数据库之前加载元数据(数据字典),Oracle数据库中object_id小于59(11g: 59,10g: 56)的为Bootstrap objects，其中包括表/索引/集群对象,Bootstrap objects包含数据库中重要的元数据，是启动实例的必需对象。Bootstrap objects对象解析结果如下所示，
图1 Bootstrap objects对象解析表
二、 数据库启动过程调试
STARTUP MOUNT;
ALTER SESSION SET EVENTS '10046 TRACE NAMECONTEXT FOREVER,LEVEL 12';
ALTER DATABASE OPEN;
ALTER SESSION SET EVENTS '10046 TRACE NAMECONTEXT OFF';
SHOW PARAMETER USER_DUMP_DEST
ORADEBUG SETMYPID
ORADEBUG TRACEFILE_NAME
图2 创建及查询Bootstrap$表
---创建bootstrap对象: 59 个
[oracle@sourcedb ~]$ egrep -in '^create' /u01/app/oracle/diag/rdbms/epmsn/epmsn/trace/epmsn_ora_21827.trc
167:create table bootstrap$ (
252:CREATE ROLLBACK SEGMENT SYSTEM STORAGE( INITIAL 112K NEXT 56K MINEXTENTS 1MAXEXTENTS 32765 OBJNO 0 EXTENTS (FILE 1 BLOCK 128))
259:CREATE CLUSTER C_OBJ#("OBJ#"NUMBER) PCTFREE 5 PCTUSED 40 INITRANS 2 MAXTRANS 255 STORAGE ( INITIAL 136K NEXT 200K MINEXTENTS 1MAXEXTENTS 2147483645 PCTINCREASE 0 OBJNO 2 EXTENTS (FILE 1 BLOCK 144)) SIZE800
266:CREATE INDEX I_OBJ# ON CLUSTER C_OBJ#PCTFREE 10 INITRANS 2 MAXTRANS 255 STORAGE ( INITIAL 64K NEXT 1024K MINEXTENTS 1 MAXEXTENTS 2147483645 PCTINCREASE 0OBJNO 3 EXTENTS (FILE 1 BLOCK 168))
276:CREATE TABLE TAB$("OBJ#"
283:CREATE TABLE CLU$("OBJ#"
290:CREATE CLUSTER C_TS#("TS#"NUMBER) PCTFREE 10 PCTUSED 40 INITRANS 2 MAXTRANS 255 STORAGE ( INITIAL 64K NEXT 1024K MINEXTENTS 1MAXEXTENTS 2147483645 PCTINCREASE 0 OBJNO 6 EXTENTS (FILE 1 BLOCK 176))
297:CREATE INDEX I_TS# ON CLUSTER C_TS#PCTFREE 10 INITRANS 2 MAXTRANS 255 STORAGE ( INITIAL 64K NEXT 1024K MINEXTENTS 1 MAXEXTENTS 2147483645 PCTINCREASE 0OBJNO 7 EXTENTS (FILE 1 BLOCK 184))
307:CREATE CLUSTERC_FILE#_BLOCK#("TS#" NUMBER,"SEGFILE#" NUMBER,"SEGBLOCK#"NUMBER) PCTFREE 10 PCTUSED 40 INITRANS 2 MAXTRANS 255 STORAGE ( INITIAL 24K NEXT 1024K MINEXTENTS 1MAXEXTENTS 2147483645 PCTINCREASE 0 OBJNO 8 EXTENTS (FILE 1 BLOCK 192)) SIZE225
314:CREATE INDEX I_FILE#_BLOCK# ON CLUSTERC_FILE#_BLOCK# PCTFREE 10 INITRANS 2 MAXTRANS 255 STORAGE ( INITIAL 64K NEXT 1024K MINEXTENTS 1MAXEXTENTS 2147483645 PCTINCREASE 0 OBJNO 9 EXTENTS (FILE 1 BLOCK 200))
324:CREATE CLUSTERC_USER#("USER#" NUMBER) PCTFREE 10 PCTUSED 40 INITRANS 2 MAXTRANS 255STORAGE ( INITIAL 64K NEXT 1024KMINEXTENTS 1 MAXEXTENTS 2147483645 PCTINCREASE 0 OBJNO 10 EXTENTS (FILE 1 BLOCK208)) SIZE 372
331:CREATE INDEX I_USER# ON CLUSTER C_USER#PCTFREE 10 INITRANS 2 MAXTRANS 255 STORAGE ( INITIAL 64K NEXT 1024K MINEXTENTS 1 MAXEXTENTS 2147483645 PCTINCREASE 0OBJNO 11 EXTENTS (FILE 1 BLOCK 216))
341:CREATE TABLE FET$("TS#" N
348:CREATE TABLE UET$("SEGFIL
355:CREATE TABLE SEG$("FILE#"
362:CREATE TABLE UNDO$("US#"
369:CREATE TABLE TS$("TS#" NU
376:CREATE TABLE FILE$("FILE#
383:CREATE TABLE OBJ$("OBJ#"
390:CREATE TABLE IND$("OBJ#"
397:CREATE TABLE ICOL$("OBJ#"
404:CREATE TABLE COL$("OBJ#"
411:CREATE TABLE USER$("USER#
418:CREATE TABLE PROXY_DATA$(
425:CREATE UNIQUE INDEX I_PROXY_DATA$ ONPROXY_DATA$(CLIENT#,PROXY#) PCTFREE 10 INITRANS 2 MAXTRANS 255 STORAGE ( INITIAL 64K NEXT 1024K MINEXTENTS 1MAXEXTENTS 2147483645 PCTINCREASE 0 OBJNO 24 EXTENTS (FILE 1 BLOCK 256))
435:CREATE TABLE PROXY_ROLE_D
442:CREATE INDEX I_PROXY_ROLE_DATA$_1 ONPROXY_ROLE_DATA$(CLIENT#,PROXY#) PCTFREE 10 INITRANS 2 MAXTRANS 255 STORAGE( INITIAL 64K NEXT 1024K MINEXTENTS 1MAXEXTENTS 2147483645 PCTINCREASE 0 OBJNO 26 EXTENTS (FILE 1 BLOCK 272))
452:CREATE UNIQUE INDEXI_PROXY_ROLE_DATA$_2 ON PROXY_ROLE_DATA$(CLIENT#,PROXY#,ROLE#) PCTFREE 10INITRANS 2 MAXTRANS 255 STORAGE ( INITIAL 64K NEXT 1024K MINEXTENTS 1 MAXEXTENTS 2147483645 PCTINCREASE 0OBJNO 27 EXTENTS (FILE 1 BLOCK 280))
462:CREATE TABLE CON$("OWNER#
469:CREATE CLUSTER C_COBJ#("OBJ#"NUMBER) PCTFREE 0 PCTUSED 50 INITRANS 2 MAXTRANS 255 STORAGE ( INITIAL 56K NEXT 1024K MINEXTENTS 1MAXEXTENTS 2147483645 PCTINCREASE 0 OBJNO 29 EXTENTS (FILE 1 BLOCK 296)) SIZE300
476:CREATE INDEX I_COBJ# ON CLUSTER C_COBJ#PCTFREE 10 INITRANS 2 MAXTRANS 255 STORAGE ( INITIAL 64K NEXT 1024K MINEXTENTS 1 MAXEXTENTS 2147483645 PCTINCREASE 0OBJNO 30 EXTENTS (FILE 1 BLOCK 304))
486:CREATE TABLE CDEF$("CON#"
493:CREATE TABLE CCOL$("CON#"
500:CREATE INDEX I_TAB1 ON TAB$(BOBJ#)PCTFREE 10 INITRANS 2 MAXTRANS 255 STORAGE ( INITIAL 64K NEXT 1024K MINEXTENTS 1 MAXEXTENTS 2147483645 PCTINCREASE 0OBJNO 33 EXTENTS (FILE 1 BLOCK 312))
510:CREATE UNIQUE INDEX I_UNDO1 ONUNDO$(US#) PCTFREE 10 INITRANS 2 MAXTRANS 255 STORAGE ( INITIAL 64K NEXT 1024K MINEXTENTS 1MAXEXTENTS 2147483645 PCTINCREASE 0 OBJNO 34 EXTENTS (FILE 1 BLOCK 320))
520:CREATE INDEX I_UNDO2 ON UNDO$(NAME)PCTFREE 10 INITRANS 2 MAXTRANS 255 STORAGE ( INITIAL 64K NEXT 1024K MINEXTENTS 1 MAXEXTENTS 2147483645 PCTINCREASE 0OBJNO 35 EXTENTS (FILE 1 BLOCK 328))
530:CREATE UNIQUE INDEX I_OBJ1 ONOBJ$(OBJ#,OWNER#,TYPE#) PCTFREE 10 INITRANS 2 MAXTRANS 255 STORAGE ( INITIAL 64K NEXT 1024K MINEXTENTS 1MAXEXTENTS 2147483645 PCTINCREASE 0 OBJNO 36 EXTENTS (FILE 1 BLOCK 336))
540:CREATE UNIQUE INDEX I_OBJ2 ONOBJ$(OWNER#,NAME,NAMESPACE,REMOTEOWNER,LINKNAME,SUBNAME,TYPE#,SPARE3,OBJ#)PCTFREE 10 INITRANS 2 MAXTRANS 255 STORAGE ( INITIAL 16K NEXT 104K MINEXTENTS 1 MAXEXTENTS 2147483645 PCTINCREASE 0OBJNO 37 EXTENTS (FILE 1 BLOCK 344))
550:CREATE INDEX I_OBJ3 ON OBJ$(OID$)PCTFREE 10 INITRANS 2 MAXTRANS 255 STORAGE ( INITIAL 64K NEXT 1024K MINEXTENTS 1 MAXEXTENTS 2147483645 PCTINCREASE 0OBJNO 38 EXTENTS (FILE 1 BLOCK 352))
560:CREATE INDEX I_OBJ4 ONOBJ$(DATAOBJ#,TYPE#,OWNER#) PCTFREE 10 INITRANS 2 MAXTRANS 255 STORAGE ( INITIAL 64K NEXT 1024K MINEXTENTS 1MAXEXTENTS 2147483645 PCTINCREASE 0 OBJNO 39 EXTENTS (FILE 1 BLOCK 360))
570:CREATE UNIQUE INDEX I_OBJ5 ONOBJ$(SPARE3,NAME,NAMESPACE,TYPE#,OWNER#,REMOTEOWNER,LINKNAME,SUBNAME,OBJ#)PCTFREE 10 INITRANS 2 MAXTRANS 255 STORAGE ( INITIAL 64K NEXT 1024K MINEXTENTS 1 MAXEXTENTS 2147483645 PCTINCREASE 0OBJNO 40 EXTENTS (FILE 1 BLOCK 368))
580:CREATE UNIQUE INDEX I_IND1 ONIND$(OBJ#) PCTFREE 10 INITRANS 2 MAXTRANS 255 STORAGE ( INITIAL 64K NEXT 1024K MINEXTENTS 1MAXEXTENTS 2147483645 PCTINCREASE 0 OBJNO 41 EXTENTS (FILE 1 BLOCK 376))
592:CREATE INDEX I_ICOL1 ON ICOL$(OBJ#)PCTFREE 10 INITRANS 2 MAXTRANS 255 STORAGE ( INITIAL 64K NEXT 1024K MINEXTENTS 1 MAXEXTENTS 2147483645 PCTINCREASE 0OBJNO 42 EXTENTS (FILE 1 BLOCK 384))
602:CREATE UNIQUE INDEX I_FILE1 ONFILE$(FILE#) PCTFREE 10 INITRANS 2 MAXTRANS 255 STORAGE ( INITIAL 64K NEXT 1024K MINEXTENTS 1MAXEXTENTS 2147483645 PCTINCREASE 0 OBJNO 43 EXTENTS (FILE 1 BLOCK 392))
612:CREATE UNIQUE INDEX I_FILE2 ONFILE$(TS#,RELFILE#) PCTFREE 10 INITRANS 2 MAXTRANS 255 STORAGE ( INITIAL 64K NEXT 1024K MINEXTENTS 1MAXEXTENTS 2147483645 PCTINCREASE 0 OBJNO 44 EXTENTS (FILE 1 BLOCK 400))
622:CREATE UNIQUE INDEX I_TS1 ON TS$(NAME)PCTFREE 10 INITRANS 2 MAXTRANS 255 STORAGE ( INITIAL 64K NEXT 1024K MINEXTENTS 1 MAXEXTENTS 2147483645 PCTINCREASE 0OBJNO 45 EXTENTS (FILE 1 BLOCK 408))
632:CREATE UNIQUE INDEX I_USER1 ONUSER$(NAME) PCTFREE 10 INITRANS 2 MAXTRANS 255 STORAGE ( INITIAL 64K NEXT 1024K MINEXTENTS 1MAXEXTENTS 2147483645 PCTINCREASE 0 OBJNO 46 EXTENTS (FILE 1 BLOCK 416))
642:CREATE UNIQUE INDEX I_USER2 ONUSER$(USER#,TYPE#,SPARE1,SPARE2) PCTFREE 10 INITRANS 2 MAXTRANS 255 STORAGE( INITIAL 64K NEXT 1024K MINEXTENTS 1MAXEXTENTS 2147483645 PCTINCREASE 0 OBJNO 47 EXTENTS (FILE 1 BLOCK 424))
652:CREATE UNIQUE INDEX I_COL1 ONCOL$(OBJ#,NAME) PCTFREE 10 INITRANS 2 MAXTRANS 255 STORAGE ( INITIAL 32K NEXT 104K MINEXTENTS 1 MAXEXTENTS2147483645 PCTINCREASE 0 OBJNO 48 EXTENTS (FILE 1 BLOCK 432))
662:CREATE INDEX I_COL2 ON COL$(OBJ#,COL#)PCTFREE 10 INITRANS 2 MAXTRANS 255 STORAGE ( INITIAL 32K NEXT 104K MINEXTENTS 1 MAXEXTENTS 2147483645 PCTINCREASE 0OBJNO 49 EXTENTS (FILE 1 BLOCK 440))
672:CREATE UNIQUE INDEX I_COL3 ONCOL$(OBJ#,INTCOL#) PCTFREE 10 INITRANS 2 MAXTRANS 255 STORAGE ( INITIAL 32K NEXT 104K MINEXTENTS 1 MAXEXTENTS2147483645 PCTINCREASE 0 OBJNO 50 EXTENTS (FILE 1 BLOCK 448))
682:CREATE UNIQUE INDEX I_CON1 ONCON$(OWNER#,NAME) PCTFREE 10 INITRANS 2 MAXTRANS 255 STORAGE ( INITIAL 64K NEXT 1024K MINEXTENTS 1MAXEXTENTS 2147483645 PCTINCREASE 0 OBJNO 51 EXTENTS (FILE 1 BLOCK 456))
692:CREATE UNIQUE INDEX I_CON2 ONCON$(CON#) PCTFREE 10 INITRANS 2 MAXTRANS 255 STORAGE ( INITIAL 64K NEXT 1024K MINEXTENTS 1MAXEXTENTS 2147483645 PCTINCREASE 0 OBJNO 52 EXTENTS (FILE 1 BLOCK 464))
702:CREATE UNIQUE INDEX I_CDEF1 ONCDEF$(CON#) PCTFREE 10 INITRANS 2 MAXTRANS 255 STORAGE ( INITIAL 64K NEXT 1024K MINEXTENTS 1MAXEXTENTS 2147483645 PCTINCREASE 0 OBJNO 53 EXTENTS (FILE 1 BLOCK 472))
712:CREATE INDEX I_CDEF2 ON CDEF$(OBJ#)PCTFREE 10 INITRANS 2 MAXTRANS 255 STORAGE ( INITIAL 64K NEXT 1024K MINEXTENTS 1 MAXEXTENTS 2147483645 PCTINCREASE 0OBJNO 54 EXTENTS (FILE 1 BLOCK 480))
722:CREATE INDEX I_CDEF3 ON CDEF$(ROBJ#)PCTFREE 10 INITRANS 2 MAXTRANS 255 STORAGE ( INITIAL 64K NEXT 1024K MINEXTENTS 1 MAXEXTENTS 2147483645 PCTINCREASE 0OBJNO 55 EXTENTS (FILE 1 BLOCK 488))
732:CREATE INDEX I_CDEF4 ON CDEF$(ENABLED)PCTFREE 10 INITRANS 2 MAXTRANS 255 STORAGE ( INITIAL 64K NEXT 1024K MINEXTENTS 1 MAXEXTENTS 2147483645 PCTINCREASE 0OBJNO 56 EXTENTS (FILE 1 BLOCK 496))
742:CREATE INDEX I_CCOL1 ONCCOL$(CON#,COL#) PCTFREE 10 INITRANS 2 MAXTRANS 255 STORAGE ( INITIAL 64K NEXT 1024K MINEXTENTS 1MAXEXTENTS 2147483645 PCTINCREASE 0 OBJNO 57 EXTENTS (FILE 1 BLOCK 504))
752:CREATE UNIQUE INDEX I_CCOL2 ONCCOL$(CON#,INTCOL#) PCTFREE 10 INITRANS 2 MAXTRANS 255 STORAGE ( INITIAL 64K NEXT 1024K MINEXTENTS 1 MAXEXTENTS2147483645 PCTINCREASE 0 OBJNO 58 EXTENTS (FILE 1 BLOCK 512))
[oracle@sourcedb ~]$ egrep -in '^create'/u01/app/oracle/diag/rdbms/epmsn/epmsn/trace/epmsn_ora_21827.trc|wc -l
59
*****查询extent占用情况
[oracle@sourcedb ~]$
set linesize 200 pagesize 200
col owner for a10
col segment_name for a20
col segment_type for a20
selectowner,segment_name,segment_type,EXTENT_ID,file_id,block_id,BLOCKS fromdba_extents where file_id=1 and 520 between block_id and block_id + blocks -1;
OWNER SEGMENT_NAME SEGMENT_TYPE EXTENT_ID FILE_ID BLOCK_ID BLOCKS
------------------------------ -------------------- ---------- ---------- --------------------
SYS BOOTSTRAP$ TABLE 0 1 520 8
SQL>
三、 bootstrap$对象解析
bootstrap$表对象解析sql:
|
--bootstrap$表对象解析.sql by 惠星星 2020.3.2 select line#, obj#, substr(sql_text, 1, 30) t_sql_1, case when substr(sql_text,8,instr(sql_text, ' ',1,2)-8)='ROLLBACK' then'SYSTEM' when substr(sql_text,8,instr(sql_text, ' ',1,2)-8) in('CLUSTER','TABLE') then substr(sql_text, instr(sql_text,'',1,2)+1,instr(sql_text,'(',1,1)-instr(sql_text,' ',1,2)-1) when substr(sql_text,8,instr(sql_text, ' ',1,2)-8)='INDEX' then substr(sql_text,instr(sql_text,' ',1,2)+1,instr(sql_text,' ',1,3)-instr(sql_text,' ',1,2)-1) when substr(sql_text,8,instr(sql_text, ' ',1,2)-8)='UNIQUE' thensubstr(sql_text, instr(sql_text,' ',1,3)+1,instr(sql_text,'',1,4)-instr(sql_text,' ',1,3)-1) else '' end name, substr(sql_text,8,instr(sql_text, ' ',1,2)-8) type, case when instr(sql_text, 'OBJNO ')<>0 then substr(sql_text,instr(sql_text, 'OBJNO '), 8) else ''end obj_no, case when instr(sql_text, 'TABNO ')<>0 then substr(sql_text,instr(sql_text, 'TABNO '), 7) else ''end TABNO, --sql_text, case when instr(sql_text, 'TABNO ')<>0 then substr(sql_text,instr(sql_text, 'CLUSTER '), instr(sql_text, ')',-1)-instr(sql_text, 'CLUSTER')+1) else '' end clus, case when instr(sql_text, 'FILE 1 ')<>0 then substr(sql_text,instr(sql_text, 'FILE 1 '), 6) else ''end file#, case when instr(sql_text, 'BLOCK ')<>0 then substr(sql_text,instr(sql_text, 'BLOCK '), 9) else ''end block# from bootstrap$ order by 2; |
bootstrap$表对象解析结果:
请见，图1 Bootstrap objects对象解析表
四、 bbed解析bootstrap$表
BBED> set dba 1,520
DBA 0x00400208(4194824 1,520)
BBED> p ktetb
struct ktetb[0], 8 bytes @108 --extent map 表示从file#1,block# 521开始的7个blocks
ub4 ktetbdba @108 0x00400209
ub4 ktetbnbk @112 0x00000007
[oracle@sourcedb ~]$ ora_rdba0x00400209
*******Welcome to use ora_rdba toolauthored by orastar.*******
*******weixin: xidoublestar*******
rdba is: 0x400209
datafile# is: 1
datablock is: 521
dump command:alter system dump datafile 1block 521;
[oracle@sourcedb ~]$
BBED> p ktemh
struct ktemh, 16 bytes @92
ub4 count_ktemh @92 0x00000001 --只有一个extent map
ub4 next_ktemh @96 0x00000000
ub4 obj_ktemh @100 0x0000003b --obj#: 59
ub4 flag_ktemh @104 0x40000000
BBED>
BBED> p hwmark_ktech
struct hwmark_ktech, 32 bytes @48
ub4 extno_ktehw @48 0x00000000
ub4 blkno_ktehw @52 0x00000003
ub4 extsize_ktehw @56 0x00000007
ub4 blkaddr_ktehw @60 0x0040020c --高水位 dba 1,524,全表扫描查询：524以下的block.
ub4 mapblk_ktehw @64 0x00000000
ub4 offset_ktehw @68 0x00000000
ub4 flblks_ktehw @72 0x00000001
ub4 blkcnt_ktehw @76 0x00000003
BBED>
[oracle@sourcedb ~]$ ora_rdba 0x0040020c
*******Welcome to use ora_rdba toolauthored by orastar.*******
*******weixin: xidoublestar*******
rdba is: 0x40020c
datafile# is: 1
datablock is: 524
dump command:alter system dump datafile 1block 524;
[oracle@sourcedb ~]$
BBED> set dba 1,521
DBA 0x00400209(4194825 1,521)
BBED> p kdbr
sb2 kdbr[0] @86 8099
sb2 kdbr[1] @88 7962
sb2 kdbr[2] @90 7573
sb2 kdbr[3] @92 7373
sb2 kdbr[4] @94 6990
sb2 kdbr[5] @96 6778
sb2 kdbr[6] @98 6573
sb2 kdbr[7] @100 5961
sb2 kdbr[8] @102 5755
sb2 kdbr[9] @104 5555
sb2 kdbr[10] @106 5334
sb2 kdbr[11] @108 5130
sb2 kdbr[12] @110 4847
sb2 kdbr[13] @112 4613
sb2 kdbr[14] @114 4366
sb2 kdbr[15] @116 3896
sb2 kdbr[16] @118 3688
sb2 kdbr[17] @120 3473
sb2 kdbr[18] @122 3193
sb2 kdbr[19] @124 2409
sb2 kdbr[20] @126 2204
sb2 kdbr[21] @128 1630
sb2 kdbr[22] @130 1421
sb2 kdbr[23] @132 1222 --该块中存储24行数据
BBED>
BBED> p *kdbr[23]
rowdata[0]
----------
ub1 rowdata[0] @1290 0x2c
BBED> x /rccccc
rowdata[0] @1290
----------
flag@1290: 0x2c (KDRHFL, KDRHFF, KDRHFH)
lock@1291: 0x01
cols@1292: 3
col 0[2] @1293: ..
col 1[2] @1296: ..
col 2[189] @1299: CREATE INDEX I_TS# ON CLUSTER C_TS# PCTFREE 10INITRANS --存储的sql语句
2MAXTRANS 255 STORAGE ( INITIAL 64K NEXT1024K MINEXTENTS 1 MAXEXTENTS 2
147483645 PCTINCREASE 0 OBJNO 7 EXTENTS(FILE 1 BLOCK 184))
***********bootstrap$存储在哪行
select
dbms_rowid.rowid_object(rowid) object_id,
dbms_rowid.rowid_relative_fno(rowid)file_id,
dbms_rowid.rowid_block_number(rowid)block_id,
dbms_rowid.rowid_row_number(rowid) frombootstrap$ where line#=59;
BBED> set dba 1,522
DBA 0x0040020a(4194826 1,522)
BBED> p *kdbr[13]
rowdata[1959]
-------------
ub1 rowdata[1959] @3485 0x2c
BBED> x /rccccccccc
rowdata[1959] @3485
-------------
flag@3485: 0x2c (KDRHFL, KDRHFF, KDRHFH)
lock@3486: 0x01
cols@3487: 3
col 0[2] @3488: .<
col 1[2] @3491: .<
col 2[272] @3494: CREATE TABLE BOOTSTRAP$("LINE#" NUMBER NOTNULL,"OBJ#"
NUMBER NOT NULL,"SQL_TEXT"VARCHAR2(4000) NOT NULL) PCTFREE 10 PCTUSED 40 I
NITRANS 1 MAXTRANS 255 STORAGE ( INITIAL 56K NEXT 1024K MINEXTENTS 1 MAXEX
TENTS 2147483645 PCTINCREASE 0 OBJNO 59EXTENTS (FILE 1 BLOCK 520))
BBED>
五、 bootstrap$的地址存储在哪？
bootstrap$的地址存储在file1,block1的kcvfhrdb(offset96)中，kcvfhrdb结构每个数据文件头都有，但只有file 1有值，其它文件为。(11.2.0.4以前)
BBED> set dba 1,1
BBED> p kcvfhrdb
ub4 kcvfhrdb @96 0x00400208
BBED> set dba 2,1
DBA 0x00800001(8388609 2,1)
BBED> p kcvfhrdb
ub4 kcvfhrdb @96 0x00000000
BBED> set dba 3,1
DBA 0x00c00001(12582913 3,1)
BBED> p kcvfhrdb
ub4 kcvfhrdb @96 0x00000000
BBED>
[oracle@sourcedb ~]$ ora_rdba 0x00400208
*******Welcome to use ora_rdba toolauthored by orastar.*******
*******weixin: xidoublestar*******
rdba is: 0x400208
datafile# is: 1
datablock is: 520
dump command:alter system dump datafile 1block 520;
[oracle@sourcedb ~]$
六、 说明
1、以上内容为个人多次测试结果，由于个人原因，如有分析不足之处还请见谅及指正。
2、文章涉及内容，请勿在生产环境模拟。
纸上得来终觉浅，绝知此事要躬行。--陆游
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