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research the DB open

From: biti_rainy <biti_rainy_at_itpub.net>
Date: 22 Apr 2004 13:55:50 -0000
Message-Id: <20040422134020.D46DC72CEB5@turing.freelists.org> 





hi


SQL> shutdown immediate


Database closed.


Database dismounted.


ORACLE instance shut down.


SQL> startup mount


ORACLE instance started.


Total System Global Area 131142648 bytes
Fixed Size 451576 bytes


Variable Size 104857600 bytes


Database Buffers 25165824 bytes


Redo Buffers 667648 bytes


Database mounted.


SQL> alter session set sql_trace = true;



Session altered.



SQL> alter database open;



Database altered.



SQL> 


(reference to the trace file )



>#1st




create table bootstrap$ ( line# number not null, obj# 
number not null, sql_text varchar2(4000) not null) storage (initial 
50K objno 56 extents (file 1 block 377))



>#2nd




select line#, sql_text 


from


bootstrap$ where obj# != :1    --- the  var should be    -1 



>#let's look at the  bootstrap$




SQL> desc bootstrap$


Name Null? Type

----------------------------------------- -------- ----------------------------


LINE# NOT NULL NUMBER



OBJ# NOT NULL NUMBER



SQL_TEXT NOT NULL VARCHAR2(4000)


SQL> 


SQL> select count(*) from bootstrap$;


57



SQL> 


SQL> select obj#,sql_text from bootstrap$ where rownum<11;
-1


8.0.0.0.0



0


CREATE ROLLBACK SEGMENT SYSTEM STORAGE ( INITIAL 112K NEXT 1024K MINEXTENTS 1 M

AXEXTENTS 32765 OBJNO 0 EXTENTS (FILE 1 BLOCK 9))


8


CREATE CLUSTER C_FILE#_BLOCK#("TS#" NUMBER,"SEGFILE#" NUMBER,"SEGBLOCK#" NUMBER)

PCTFREE 10 PCTUSED 40 INITRANS 2 MAXTRANS 255 STORAGE ( INITIAL 24K NEXT 1024K

MINEXTENTS 1 MAXEXTENTS 2147483645 PCTINCREASE 0 OBJNO 8 EXTENTS (FILE 1 BLOCK

73)) SIZE 225


9


CREATE INDEX I_FILE#_BLOCK# ON CLUSTER C_FILE#_BLOCK# PCTFREE 10 INITRANS 2 MAXT

RANS 255 STORAGE ( INITIAL 64K NEXT 1024K MINEXTENTS 1 MAXEXTENTS 2147483645 PC

TINCREASE 0 OBJNO 9 EXTENTS (FILE 1 BLOCK 81))


14


CREATE TABLE SEG$("FILE#" NUMBER NOT NULL,"BLOCK#" NUMBER NOT NULL,"TYPE#" NUMBE

R NOT NULL,"TS#" NUMBER NOT NULL,"BLOCKS" NUMBER NOT NULL,"EXTENTS" NUMBER NOT N

ULL,"INIEXTS" NUMBER NOT NULL,"MINEXTS" NUMBER NOT NULL,"MAXEXTS" NUMBER NOT NUL

L,"EXTSIZE" NUMBER NOT NULL,"EXTPCT" NUMBER NOT NULL,"USER#" NUMBER NOT NULL,"LI

STS" NUMBER,"GROUPS" NUMBER,"BITMAPRANGES" NUMBER NOT NULL,"CACHEHINT" NUMBER NO

T NULL,"SCANHINT" NUMBER NOT NULL,"HWMINCR" NUMBER NOT NULL,"SPARE1" NUMBER,"SPA

RE2" NUMBER) STORAGE ( OBJNO 14 TABNO 2) CLUSTER C_FILE#_BLOCK#(TS#,FILE#,BLOCK

#)



5


CREATE TABLE CLU$("OBJ#" NUMBER NOT NULL,"DATAOBJ#" NUMBER,"TS#" NUMBER NOT NULL

,"FILE#" NUMBER NOT NULL,"BLOCK#" NUMBER NOT NULL,"COLS" NUMBER NOT NULL,"PCTFRE

E$" NUMBER NOT NULL,"PCTUSED$" NUMBER NOT NULL,"INITRANS" NUMBER NOT NULL,"MAXTR


ANS" NUMBER NOT NULL,"SIZE$" NUMBER,"HASHFUNC" VARCHAR2(30),"HASHKEYS" NUMBER,"F
UNC" NUMBER,"EXTIND" NUMBER,"FLAGS" NUMBER,"DEGREE" NUMBER,"INSTANCES" NUMBER,"A
VGCHN" NUMBER,"SPARE1" NUMBER,"SPARE2" NUMBER,"SPARE3" NUMBER,"SPARE4" NUMBER,"S


PARE5" VARCHAR2(1000),"SPARE6" VARCHAR2(1000),"SPARE7" DATE) STORAGE ( OBJNO 5

TABNO 2) CLUSTER C_OBJ#(OBJ#)


6


CREATE CLUSTER C_TS#("TS#" NUMBER) PCTFREE 10 PCTUSED 40 INITRANS 2 MAXTRANS 255

STORAGE ( INITIAL 64K NEXT 1024K MINEXTENTS 1 MAXEXTENTS 2147483645 PCTINCREAS

E 0 OBJNO 6 EXTENTS (FILE 1 BLOCK 57))


7


CREATE INDEX I_TS# ON CLUSTER C_TS# PCTFREE 10 INITRANS 2 MAXTRANS 255 STORAGE (

INITIAL 64K NEXT 1024K MINEXTENTS 1 MAXEXTENTS 2147483645 PCTINCREASE 0 OBJNO

7 EXTENTS (FILE 1 BLOCK 65))


18


CREATE TABLE OBJ$("OBJ#" NUMBER NOT NULL,"DATAOBJ#" NUMBER,"OWNER#" NUMBER NOT N

ULL,"NAME" VARCHAR2(30) NOT NULL,"NAMESPACE" NUMBER NOT NULL,"SUBNAME" VARCHAR2(

30),"TYPE#" NUMBER NOT NULL,"CTIME" DATE NOT NULL,"MTIME" DATE NOT NULL,"STIME"

DATE NOT NULL,"STATUS" NUMBER NOT NULL,"REMOTEOWNER" VARCHAR2(30),"LINKNAME" VAR

CHAR2(128),"FLAGS" NUMBER,"OID$" RAW(16),"SPARE1" NUMBER,"SPARE2" NUMBER,"SPARE3

" NUMBER,"SPARE4" VARCHAR2(1000),"SPARE5" VARCHAR2(1000),"SPARE6" DATE) PCTFREE

10 PCTUSED 40 INITRANS 1 MAXTRANS 255 STORAGE ( INITIAL 16K NEXT 1024K MINEXTEN

TS 1 MAXEXTENTS 2147483645 PCTINCREASE 0 OBJNO 18 EXTENTS (FILE 1 BLOCK 121))


36


CREATE UNIQUE INDEX I_OBJ1 ON OBJ$(OBJ#) PCTFREE 10 INITRANS 2 MAXTRANS 255 STOR

AGE ( INITIAL 64K NEXT 1024K MINEXTENTS 1 MAXEXTENTS 2147483645 PCTINCREASE 0 O

BJNO 36 EXTENTS (FILE 1 BLOCK 217))



10 rows selected.



SQL> 





>#we can see that the bootstrap$ stored the DDL script for the  system objects  

>#let's check the  trace content 




CREATE ROLLBACK SEGMENT SYSTEM STORAGE ( INITIAL 112K NEXT 1024K MINEXTENTS 

1 MAXEXTENTS 32765 OBJNO 0 EXTENTS (FILE 1 BLOCK 9)) 




>#here create a system rollback segment header at "file 1 block 9"(LMT ,not DMT)

>#go on




CREATE CLUSTER C_OBJ#("OBJ#" NUMBER) PCTFREE 5 PCTUSED 40 INITRANS 2 MAXTRANS 

255 STORAGE ( INITIAL 136K NEXT 1024K MINEXTENTS 1 MAXEXTENTS 2147483645 

PCTINCREASE 0 OBJNO 2 EXTENTS (FILE 1 BLOCK 25)) SIZE 800




># notice that "OBJNO 2 EXTENTS (FILE 1 BLOCK 25)) SIZE 800"

>#query 




SQL> select file_id,block_id from dba_extents where segment_name = 'C_OBJ#';
1 25


1 33


1 41


1 3241


1 4441


1 4473


1 4489


1 4513


1 4529


1 4561


1 4585


1 4609


1 4641


1 4681


1 4753


1 4833


1 4873


1 12681


1 23689


1 26249



20 rows selected.




>#go on





CREATE INDEX I_OBJ# ON CLUSTER C_OBJ# PCTFREE 10 INITRANS 2 MAXTRANS 255 

STORAGE ( INITIAL 64K NEXT 1024K MINEXTENTS 1 MAXEXTENTS 2147483645 

PCTINCREASE 0 OBJNO 3 EXTENTS (FILE 1 BLOCK 49))



CREATE TABLE TAB$("OBJ#" NUMBER NOT NULL,"DATAOBJ#" NUMBER,"TS#" NUMBER NOT 

NULL,"FILE#" NUMBER NOT NULL,"BLOCK#" NUMBER NOT NULL,"BOBJ#" NUMBER,"TAB#" 

NUMBER,"COLS" NUMBER NOT NULL,"CLUCOLS" NUMBER,"PCTFREE$" NUMBER NOT NULL,

"PCTUSED$" NUMBER NOT NULL,"INITRANS" NUMBER NOT NULL,"MAXTRANS" NUMBER NOT 

NULL,"FLAGS" NUMBER NOT NULL,"AUDIT$" VARCHAR2(38) NOT NULL,"ROWCNT" NUMBER,


"BLKCNT" NUMBER,"EMPCNT" NUMBER,"AVGSPC" NUMBER,"CHNCNT" NUMBER,"AVGRLN" 
NUMBER,"AVGSPC_FLB" NUMBER,"FLBCNT" NUMBER,"ANALYZETIME" DATE,"SAMPLESIZE" 
NUMBER,"DEGREE" NUMBER,"INSTANCES" NUMBER,"INTCOLS" NUMBER NOT NULL,
"KERNELCOLS" NUMBER NOT NULL,"PROPERTY" NUMBER NOT NULL,"TRIGFLAG" NUMBER,


"SPARE1" NUMBER,"SPARE2" NUMBER,"SPARE3" NUMBER,"SPARE4" VARCHAR2(1000),

"SPARE5" VARCHAR2(1000),"SPARE6" DATE) STORAGE ( OBJNO 4 TABNO 1) CLUSTER 

C_OBJ#(OBJ#)





># from tab$ , notice that  "STORAGE ( OBJNO 4 TABNO 1) CLUSTER C_OBJ#(OBJ#)"

># what are the  "objno 4 tabno 1" ?   we can look up the tab$  via  "cluster C_OBJ#(OBJ#)"




SQL> select * from tab$ where obj# = 4 and tab# = 1;



OBJ# DATAOBJ# TS# FILE# BLOCK# BOBJ# TAB#

---------- ---------- ---------- ---------- ---------- ---------- ----------
COLS CLUCOLS PCTFREE$ PCTUSED$ INITRANS MAXTRANS FLAGS

---------- ---------- ---------- ---------- ---------- ---------- ----------
AUDIT$ ROWCNT BLKCNT EMPCNT


-------------------------------------- ---------- ---------- ----------


AVGSPC CHNCNT AVGRLN AVGSPC_FLB FLBCNT ANALYZETI SAMPLESIZE

---------- ---------- ---------- ---------- ---------- --------- ----------
DEGREE INSTANCES INTCOLS KERNELCOLS PROPERTY TRIGFLAG SPARE1

---------- ---------- ---------- ---------- ---------- ---------- ----------
SPARE2 SPARE3



---------- ----------


SPARE4





SPARE5





SPARE6





4 2 0 1 25 2 1


37 1 0 0 0 0 17

-------------------------------- 921 428 83


2381 0 139 6368 7 11-AUG-03 921



37 37 1024 0 0





06-AUG-03



SQL> 

 


># now  we  see that     from here to DB complete open, all the objects storage come from fixed  file# and block#

>#  so if these system block  corrupted ,the  DB can not open 






  one   year  ago , i   thought that  oracle can  query much information via the  data  dictionary tables/views 
but , how to found the basic information . the data are stored in system but we can query it on  sql . user table's structure information come from DICT tables , but how about the  DICT table's structure information ?



 so i  do the test ,and  find the egg  ----  bootstrap$
the egg can  hatch the   c_obj$ and tab$ ... 



i guess the bootstrap$'s structure or  storage information are also stored in the oracle  code (like oracle.exe)
and when opening , oracle only create the  structrue(include the storage information)  in the shared pool but do not create the segment in the system tablespace . and , the "DDL"  do not live in the shared pool,we can not query it in  v$sql/v$sqlarea  .













  



Best regards



yahoo id: feng_chunpei


A new dba from china









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Received on Thu Apr 22 2004 - 08:50:52 CDT












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