Oracle 控制文件存储解析

OCM之家 2021-04-16

284

点击上方“公众号” 可以订阅哦！

控制文件块内容分布

SQL> SELECT TYPE, 
  1         RECORD_SIZE, 
  2         RECORDS_TOTAL, 
  3         RECORD_SIZE*RECORDS_TOTAL, 
  4         ceil(record_size*records_total/((8*1024)-24))
  5    FROM v$controlfile_record_section;
 
TYPE                         RECORD_SIZE RECORDS_TOTAL SIZE     BLOCK#    BLOCKS
---------------------------- ----------- ------------- ------- ------- ---------
TITLE                                  1             1               1         1
DATABASE                             316             1     316       2         1
CKPT PROGRESS                       8180            11   89980       3        12
REDO THREAD                          256             8    2048      15         1
REDO LOG                              72            16    1152      16         1
DATAFILE                             520          1024  532480      17        66
FILENAME                             524          4146 2172504      83       266
TABLESPACE                           180          1024  184320     349        23
TEMPORARY FILENAME                    56          1024   57344     372         8
RMAN CONFIGURATION                  1108            50   55400     380         7
LOG HISTORY                           56           292   16352     387         3
OFFLINE RANGE                        200          1063  212600     390        27
ARCHIVED LOG                         584            28   16352     417         3
BACKUP SET                            96          1022   98112     420        13
BACKUP PIECE                         780          1006  784680     433        97
BACKUP DATAFILE                      200          1063  212600     530        27
BACKUP REDOLOG                        76           215   16340     557         3
DATAFILE COPY                        736          1000  736000     560        91
BACKUP CORRUPTION                     44          1115   49060     651         7
COPY CORRUPTION                       40          1227   49080     658         7
DELETED OBJECT                        20           818   16360     665         3
PROXY COPY                           928          1004  931712     668       115
BACKUP SPFILE                        124           131   16244     783         2
DATABASE INCARNATION                  56           292   16352     785         3
FLASHBACK LOG                         84          2048  172032     788        22
RECOVERY DESTINATION                 180             1     180     810         1
INSTANCE SPACE RESERVATION            28          1055   29540     811         4
REMOVABLE RECOVERY FILES              32          1000   32000     815         4
RMAN STATUS                          116           141   16356     819         3
THREAD INSTANCE NAME MAPPING          80             8     640     822         1
MTTR                                 100             8     800     823         1
DATAFILE HISTORY                     568            57   32376     824         4
STANDBY DATABASE MATRIX              400           128   51200     828         7
GUARANTEED RESTORE POINT             256          2048  524288     835        65
RESTORE POINT                        256          2108  539648     900        67
DATABASE BLOCK CORRUPTION             80          8384  670720     967        83
ACM OPERATION                        104            64    6656    1050         1
FOREIGN ARCHIVED LOG                 604          1002  605208    1051        75
PDB RECORD                           780            10    7800    1126         1
AUXILIARY DATAFILE COPY              584           128   74752    1127        10
MULTI INSTANCE REDO APPLY            556             1     556    1137         1
PDBINC RECORD                        144           113   16272    1139         2
TABLESPACE KEY HISTORY               108           151   16308    1141         2

下面找几个块，进行解析，了解控制文件数据存储方式。

文件头块

BBED> set filename '/oradata/ORCL/control01.ctl'
FILENAME /oradata/ORCL/control01.ctl
BBED> set block 0
BLOCK# 0
BBED> dump
File: /oradata/ORCL/control01.ctl (0)
Block: 0 Offsets: 0 to 511 Dba:0x00000000
00c20000 0000c0ff 00000000 00000004 10fa0000 00400000 76040000 7d7c7b7a
a0810000 00000000 00000000 00000000 00000000 00000000 00000000 00000000
00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000

offset 1：c2，blocksize

82=4096
a2=8192
c2=16384
e2=32768

offset 6~7：c0ff
offset 16~17：10fa，file related to growth(unit block)
offset 20~21
blocksize：0040–>4000(0100 0000 0000 0000)=16384，控制文件每个块的内容由两个8k块构成，其中一个为影子块
offset 24~25：7604，块的数量
offset 28~31：7d7c7b7a，magic number
offset 32~33：a081

1 号块：文件头信息

BBED

BBED> set block 1
BLOCK# 1
BBED> dump
File: /oradata/ORCL/control01.ctl (0)
Block: 1 Offsets: 0 to 511 Dba:0x00000000
15c20000 01000000 00000000 00000104 dc0c0000 00000000 00000013 56e1dd5c
4f52434c 00000000 1e100000 76040000 00400000 00000100 00000000 00000000
00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000
b05f355d d795683d bbe60b00 00800000 65cac03d 00000000 00000000 00000000
00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000

DUMP

DUMP OF CONTROL FILES, Seq # 4126 = 0x101e
V10 STYLE FILE HEADER:
Compatibility Vsn = 318767104=0x13000000
Db ID=1558045014=0x5cdde156, Db Name=’ORCL’
Activation ID=0=0x0
Control Seq=4126=0x101e, File size=1142=0x476
File Number=0, Blksiz=16384, File Type=1 CONTROL

分析

offset 0~0：15，表示mask
offset 1~1：c2，表示blocksize
offset 4~4：01，表示No.1 block
offset 24~27：00000013（倒序），表示Version(13.0.0.0)
此处对应dump：Compatibility Vsn = 318767104=0x13000000
offset 28~31：56e1dd5c（倒序），表示DBID
此处对应dump：Db ID=1558045014=0x5cdde156
offset 32~39：4f52434c 00000000，表示DBNAME
此处对应dump：Db Name=’ORCL’

下面对比一下16进制转码和dump获取的值，即可得证

SQL> select dump('ORCL') from dual;
 
DUMP('ORCL')
--------------------------------------------------
Typ=96 Len=4: 79,82,67,76
 
SQL> select to_number('4f','xx'),
 2          to_number('52','xx'),
 3          to_number('43','xx'),
 4          to_number('4c','xx')
 5     from dual;
 
TO_NUMBER('4F','XX') TO_NUMBER('52','XX') TO_NUMBER('43','XX') TO_NUMBER('4C','XX')
-------------------- -------------------- -------------------- --------------------
          79               82           67           76

offset 40~41：1e10，表示sequence
此处对应dump：Control Seq=4126=0x101e
offset 44~45：7604（倒序），表示file size(block Number)
此处对应dump：File size=1142=0x476
offset 49~50：0400（倒序），表示blocksize 16384
此处对应dump：Blksiz=16384
offset 53~54：0000，表示fileNo
此处对应dump：File Number=0
offset 55~56：0100，表示fileType
此处对应dump：File Type=1 CONTROL
offset 105~108：bbe60b00（倒序），表示控制文件SCN
Controlfile Checkpointed at scn: 0x00000000000be6bb

3 号块：CHECKPOINT PROGRESS RECORDS

BBED

BBED> set block 3
BLOCK# 3
BBED> dump
File: /oradata/ORCL/control01.ctl (0)
Block: 3 Offsets: 0 to 511 Dba:0x00000000
15c20000 03000000 00000000 00000104 4abb0000 01000000 00000000 00000000
ffffffff ffffffff ffff0000 13000000 c8790000 00000000 39eb0b00 00000000
90cac03d d695683d 01000000 00000000 24a9c03d b05f355d 00000000 00000000
00000000 00000000 00000000 00000000 00000000 00000000 00000000 13000000
01000000 0000d7cc 00000000 00000000 00000000 00000000 00000000 00000000
00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000

DUMP

CHECKPOINT PROGRESS RECORDS
(size = 8180, compat size = 8180, section max = 11, section in-use = 0,
last-recid= 0, old-recno = 0, last-recno = 0)
(extent = 1, blkno = 2, numrecs = 11)
THREAD #1 - status:0x1 flags:0x0 dirty:0
low cache rba:(0xffffffff.ffffffff.ffff) on disk rba:(0x13.79c8.0)
on disk scn: 0x00000000000beb39 03/26/2020 06:15:44
resetlogs scn: 0x0000000000000001 01/21/2020 08:31:18
heartbeat: 1036034387 mount id: 1563778992

分析

offset 0~0：15，表示mask
offset 1~1：c2，表示blocksize
offset 4~4：033，表示No. 3 block
offset 15~16：各版本不发生变化
offset 20~20：01，表示thread status

1 表示线程关闭
2 表示线程出于open状态

offset 32~41：ffffffff ffffffff ffff，表示low cache rba
此处对应dump：low cache rba:(0xffffffff.ffffffff.ffff)
offset 42~51：0000 13000000 c8790000，表示on disk rba
此处对应dump：on disk rba:(0x13.79c8.0)
offset 56~59：39eb0b00，表示on disk scn
此处对应dump：on disk scn: 0x00000000000beb39
offset 72~75：01000000，表示resetlogs scn
此处对应dump：resetlogs scn: 0x0000000000000001