Oracle 10g 数据文件的第一个数据块结构

一.数据文件的第一个数据块结构kcvfh

BBED> set file 1
        FILE#           1

BBED> set block 1
        BLOCK#          1

--查看第一个数据块的整体结构
BBED> map /v
 File: /u01/app/oracle/oradata/ORCL/datafile/o1_mf_system_bc7ld3sf_.dbf (1)
 Block: 1                                     Dba:0x00400001
------------------------------------------------------------
 Data File Header

 struct kcvfh, 676 bytes                    @0       
    struct kcvfhbfh, 20 bytes               @0       
    struct kcvfhhdr, 76 bytes               @20      
    ub4 kcvfhrdb                            @96      
    struct kcvfhcrs, 8 bytes                @100     
    ub4 kcvfhcrt                            @108     
    ub4 kcvfhrlc                            @112     
    struct kcvfhrls, 8 bytes                @116     
    ub4 kcvfhbti                            @124     
    struct kcvfhbsc, 8 bytes                @128     
    ub2 kcvfhbth                            @136     
    ub2 kcvfhsta                            @138     
    struct kcvfhckp, 36 bytes               @484     
    ub4 kcvfhcpc                            @140     
    ub4 kcvfhrts                            @144     
    ub4 kcvfhccc                            @148     
    struct kcvfhbcp, 36 bytes               @152     
    ub4 kcvfhbhz                            @312     
    struct kcvfhxcd, 16 bytes               @316     
    word kcvfhtsn                           @332     
    ub2 kcvfhtln                            @336     
    text kcvfhtnm[30]                       @338     
    ub4 kcvfhrfn                            @368     
    struct kcvfhrfs, 8 bytes                @372     
    ub4 kcvfhrft                            @380     
    struct kcvfhafs, 8 bytes                @384     
    ub4 kcvfhbbc                            @392     
    ub4 kcvfhncb                            @396     
    ub4 kcvfhmcb                            @400     
    ub4 kcvfhlcb                            @404     
    ub4 kcvfhbcs                            @408     
    ub2 kcvfhofb                            @412     
    ub2 kcvfhnfb                            @414     
    ub4 kcvfhprc                            @416     
    struct kcvfhprs, 8 bytes                @420     
    struct kcvfhprfs, 8 bytes               @428     
    ub4 kcvfhtrt                            @444     

 ub4 tailchk                                @8188    

BBED>

--print结构 kcvfh
BBED> print kcvfh
struct kcvfh, 676 bytes                     @0       
   struct kcvfhbfh, 20 bytes                @0       
      ub1 type_kcbh                         @0        0x0b
      ub1 frmt_kcbh                         @1        0xa2
      ub1 spare1_kcbh                       @2        0x00
      ub1 spare2_kcbh                       @3        0x00
      ub4 rdba_kcbh                         @4        0x00400001
      ub4 bas_kcbh                          @8        0x00000000
      ub2 wrp_kcbh                          @12       0x0000
      ub1 seq_kcbh                          @14       0x01
      ub1 flg_kcbh                          @15       0x04 (KCBHFCKV)
      ub2 chkval_kcbh                       @16       0xd5f6
      ub2 spare3_kcbh                       @18       0x0000
   struct kcvfhhdr, 76 bytes                @20      
      ub4 kccfhswv                          @20       0x00000000
      ub4 kccfhcvn                          @24       0x0a200100
      ub4 kccfhdbi                          @28       0x533ddaa4
      text kccfhdbn[0]                      @32      O
      text kccfhdbn[1]                      @33      R
      text kccfhdbn[2]                      @34      C
      text kccfhdbn[3]                      @35      L
      text kccfhdbn[4]                      @36       
      text kccfhdbn[5]                      @37       
      text kccfhdbn[6]                      @38       
      text kccfhdbn[7]                      @39       
      ub4 kccfhcsq                          @40       0x0000022d
      ub4 kccfhfsz                          @44       0x0000f000
      s_blkz kccfhbsz                       @48       0x00
      ub2 kccfhfno                          @52       0x0001
      ub2 kccfhtyp                          @54       0x0003
      ub4 kccfhacid                         @56       0x00000000
      ub4 kccfhcks                          @60       0x00000000
      text kccfhtag[0]                      @64       
      text kccfhtag[1]                      @65       
      text kccfhtag[2]                      @66       
      text kccfhtag[3]                      @67       
      text kccfhtag[4]                      @68       
      text kccfhtag[5]                      @69       
      text kccfhtag[6]                      @70       
      text kccfhtag[7]                      @71       
      text kccfhtag[8]                      @72       
      text kccfhtag[9]                      @73       
      text kccfhtag[10]                     @74       
      text kccfhtag[11]                     @75       
      text kccfhtag[12]                     @76       
      text kccfhtag[13]                     @77       
      text kccfhtag[14]                     @78       
      text kccfhtag[15]                     @79       
      text kccfhtag[16]                     @80       
      text kccfhtag[17]                     @81       
      text kccfhtag[18]                     @82       
      text kccfhtag[19]                     @83       
      text kccfhtag[20]                     @84       
      text kccfhtag[21]                     @85       
      text kccfhtag[22]                     @86       
      text kccfhtag[23]                     @87       
      text kccfhtag[24]                     @88       
      text kccfhtag[25]                     @89       
      text kccfhtag[26]                     @90       
      text kccfhtag[27]                     @91       
      text kccfhtag[28]                     @92       
      text kccfhtag[29]                     @93       
      text kccfhtag[30]                     @94       
      text kccfhtag[31]                     @95       
   ub4 kcvfhrdb                             @96       0x00400179
   struct kcvfhcrs, 8 bytes                 @100     
      ub4 kscnbas                           @100      0x00000005
      ub2 kscnwrp                           @104      0x0000
   ub4 kcvfhcrt                             @108      0x33c88f35
   ub4 kcvfhrlc                             @112      0x33cecf37
   struct kcvfhrls, 8 bytes                 @116     
      ub4 kscnbas                           @116      0x00073e32
      ub2 kscnwrp                           @120      0x0000
   ub4 kcvfhbti                             @124      0x00000000
   struct kcvfhbsc, 8 bytes                 @128     
      ub4 kscnbas                           @128      0x00000000
      ub2 kscnwrp                           @132      0x0000
   ub2 kcvfhbth                             @136      0x0000
   ub2 kcvfhsta                             @138      0x2004 (KCVFHOFZ)
   struct kcvfhckp, 36 bytes                @484     
      struct kcvcpscn, 8 bytes              @484     
         ub4 kscnbas                        @484      0x00073e33
         ub2 kscnwrp                        @488      0x0000
      ub4 kcvcptim                          @492      0x33cecf3e
      ub2 kcvcpthr                          @496      0x0001
      union u, 12 bytes                     @500     
         struct kcvcprba, 12 bytes          @500     
            ub4 kcrbaseq                    @500      0x00000001
            ub4 kcrbabno                    @504      0x00000002
            ub2 kcrbabof                    @508      0x0010
      ub1 kcvcpetb[0]                       @512      0x02
      ub1 kcvcpetb[1]                       @513      0x00
      ub1 kcvcpetb[2]                       @514      0x00
      ub1 kcvcpetb[3]                       @515      0x00
      ub1 kcvcpetb[4]                       @516      0x00
      ub1 kcvcpetb[5]                       @517      0x00
      ub1 kcvcpetb[6]                       @518      0x00
      ub1 kcvcpetb[7]                       @519      0x00
   ub4 kcvfhcpc                             @140      0x00000043
   ub4 kcvfhrts                             @144      0x33cecf1e
   ub4 kcvfhccc                             @148      0x00000042
   struct kcvfhbcp, 36 bytes                @152     
      struct kcvcpscn, 8 bytes              @152     
         ub4 kscnbas                        @152      0x00000000
         ub2 kscnwrp                        @156      0x0000
      ub4 kcvcptim                          @160      0x00000000
      ub2 kcvcpthr                          @164      0x0000
      union u, 12 bytes                     @168     
         struct kcvcprba, 12 bytes          @168     
            ub4 kcrbaseq                    @168      0x00000000
            ub4 kcrbabno                    @172      0x00000000
            ub2 kcrbabof                    @176      0x0000
      ub1 kcvcpetb[0]                       @180      0x00
      ub1 kcvcpetb[1]                       @181      0x00
      ub1 kcvcpetb[2]                       @182      0x00
      ub1 kcvcpetb[3]                       @183      0x00
      ub1 kcvcpetb[4]                       @184      0x00
      ub1 kcvcpetb[5]                       @185      0x00
      ub1 kcvcpetb[6]                       @186      0x00
      ub1 kcvcpetb[7]                       @187      0x00
   ub4 kcvfhbhz                             @312      0x00000000
   struct kcvfhxcd, 16 bytes                @316     
      ub4 space_kcvmxcd[0]                  @316      0x00000000
      ub4 space_kcvmxcd[1]                  @320      0x00000000
      ub4 space_kcvmxcd[2]                  @324      0x00000000
      ub4 space_kcvmxcd[3]                  @328      0x00000000
   word kcvfhtsn                            @332      0
   ub2 kcvfhtln                             @336      0x0006
   text kcvfhtnm[0]                         @338     S
   text kcvfhtnm[1]                         @339     Y
   text kcvfhtnm[2]                         @340     S
   text kcvfhtnm[3]                         @341     T
   text kcvfhtnm[4]                         @342     E
   text kcvfhtnm[5]                         @343     M
   text kcvfhtnm[6]                         @344      
   text kcvfhtnm[7]                         @345      
   text kcvfhtnm[8]                         @346      
   text kcvfhtnm[9]                         @347      
   text kcvfhtnm[10]                        @348      
   text kcvfhtnm[11]                        @349      
   text kcvfhtnm[12]                        @350      
   text kcvfhtnm[13]                        @351      
   text kcvfhtnm[14]                        @352      
   text kcvfhtnm[15]                        @353      
   text kcvfhtnm[16]                        @354      
   text kcvfhtnm[17]                        @355      
   text kcvfhtnm[18]                        @356      
   text kcvfhtnm[19]                        @357      
   text kcvfhtnm[20]                        @358      
   text kcvfhtnm[21]                        @359      
   text kcvfhtnm[22]                        @360      
   text kcvfhtnm[23]                        @361      
   text kcvfhtnm[24]                        @362      
   text kcvfhtnm[25]                        @363      
   text kcvfhtnm[26]                        @364      
   text kcvfhtnm[27]                        @365      
   text kcvfhtnm[28]                        @366      
   text kcvfhtnm[29]                        @367      
   ub4 kcvfhrfn                             @368      0x00000001
   struct kcvfhrfs, 8 bytes                 @372     
      ub4 kscnbas                           @372      0x00000000
      ub2 kscnwrp                           @376      0x0000
   ub4 kcvfhrft                             @380      0x00000000
   struct kcvfhafs, 8 bytes                 @384     
      ub4 kscnbas                           @384      0x00000000
      ub2 kscnwrp                           @388      0x0000
   ub4 kcvfhbbc                             @392      0x00000000
   ub4 kcvfhncb                             @396      0x00000000
   ub4 kcvfhmcb                             @400      0x00000000
   ub4 kcvfhlcb                             @404      0x00000000
   ub4 kcvfhbcs                             @408      0x00000000
   ub2 kcvfhofb                             @412      0x000a
   ub2 kcvfhnfb                             @414      0x000a
   ub4 kcvfhprc                             @416      0x33ce5d9c
   struct kcvfhprs, 8 bytes                 @420     
      ub4 kscnbas                           @420      0x0006ca36
      ub2 kscnwrp                           @424      0x0000
   struct kcvfhprfs, 8 bytes                @428     
      ub4 kscnbas                           @428      0x00000000
      ub2 kscnwrp                           @432      0x0000
   ub4 kcvfhtrt                             @444      0x00000000

BBED> 

注，print出的值可能是不完整的，如果想查看详细的值，最好用dump

二.数据字典X$KCVFH

　　X$KCVFH（参考dbsnake博客）的值与kcvfh是相对应的

序号	Column Name	Description
1	ADDR RAW(4)	ADDRESS
2	INDX NUMBER	INDEX
3	INST_ID NUMBER	INSTANCE ID
4	HXFIL NUMBER	FILE#，Datafile number (from control file)
5	HXONS NUMBER	ONLINE | OFFLINE (from control file),HXONS为 0表示 ‘OFFLINE’,为其他值表示 ‘ONLINE’
6	HXSTS VARCHAR2(16)
7	HXERR NUMBER	ERROR，decode(HXERR, 0, NULL, 1,’FILE MISSING’,2,’OFFLINE NORMAL’, 3,’NOT VERIFIED’, 4,’FILE NOT FOUND’,5,’CANNOT OPEN FILE’, 6,’CANNOT READ HEADER’, 7,’CORRUPT HEADER’,8,’WRONG FILE TYPE’, 9,’WRONG DATABASE’, 10,’WRONG FILE NUMBER’,11,’WRONG FILE CREATE’, 12,’WRONG FILE CREATE’, 16,’DELAYED OPEN’,14, ‘WRONG RESETLOGS’, 15,’OLD CONTROLFILE’, ‘UNKNOWN ERROR’)
8	HXVER NUMBER	FORMAT，Indicates the format for the header block. The possible values are 6, 7, 8, or 0. 6  - indicates Oracle Version 6；7 – indicates Oracle Version 7；8 – indicates Oracle Version 8；0  - indicates the format could not be determined (for example, the header could not be read)
9	FHSWV NUMBER
10	FHCVN NUMBER	Compatibility Vsn
11	FHDBI NUMBER	DBID
12	FHDBN VARCHAR2(9)	DB NAME
13	FHCSQ NUMBER	controlfile sequence number
14	FHFSZ NUMBER	BLOCKS, Current datafile size in blocks
15	FHBSZ NUMBER	datafile block size
16	FHFNO NUMBER	Tablespace datafile number
17	FHTYP NUMBER	Type:
		1 control file
		2 redo log file
		3 vanilla db file; that is, normal data, index, and undo blocks
		4 backup control file
		5 backup piece
		6 temporary db file
18	FHRDB NUMBER	Root dba: This field only occurs in data file #1, and is the location of blocks required during bootstrapping the data dictionary (bootstrap$)
19	FHCRS VARCHAR2(16)	CREATION_CHANGE#，Datafile creation change#
20	FHCRT VARCHAR2(20)	CREATION_TIME，Datafile creation timestamp
21	FHRLC VARCHAR2(20)	RESETLOGS_TIME, Resetlogs timestamp
22	FHRLC_I NUMBER	reset logs count
23	FHRLS VARCHAR2(16)	RESETLOGS_CHANGE#, Resetlogs change#
24	FHPRC VARCHAR2(20)	prev reset logs timestamp
25	FHPRC_I NUMBER	prev reset logs count
26	FHPRS VARCHAR2(16)	prev reset logs SCN
27	FHBTI VARCHAR2(20)	Time the backup started, Updated when executing BEGIN BACKUP on the tablespace. RMAN does not update this field.
28	FHBSC VARCHAR2(16)	System change number when backup started, Updated when executing BEGIN BACKUP on the tablespace. RMAN does not update this field.
29	FHBTH NUMBER	Thread when when backup started, Updated when executing BEGIN BACKUP on the tablespace. RMAN does not update this field.
30	FHSTA NUMBER	The value for the column X$KCVFH.FHSTA (file header status) for an open database with an online datafiles in versions prior to version 10 were all 4, indicating an online fuzzy status.  With version 10 of Oracle the first system tablespace datafile will have a different status of 8196 if the datafile is online and the database is open and not in backup mode. In Oracle , the X$KCVFH.FHSTA column will show 8196 for system data file if COMPATIBLE is set to 10.0.0.0 or higher.  The value of 8196 is a value of 0×04, as in previous releases, plus an AND’d value of 0×2000 (8192) for internal uses. If COMPATIBLE is set to 9.2.0 (lowest possible value for Oracle ), the FHSTA column for system datafile will have a value of 4.   In Oracle, the COMPATIBLE value is irreversible if advanced to a higher value. So the value of 8196 for the fhsta (status) column for the first system tablespace datafile is normal.
31	FHSCN VARCHAR2(16)	CHECKPOINT_CHANGE#, Datafile checkpoint change#, Updated on every checkpoint, but not when in Hot backup state (not online backups). This must remain untouched when you are in hot backup mode, because you might get checkpoints between the BEGIN BACKUP and when you actually start the copying process.
32	FHTIM VARCHAR2(20)	CHECKPOINT_TIME, Datafile checkpoint timestamp
33	FHTHR NUMBER	THREAD#
34	FHRBA_SEQ NUMBER	SEQUENCE，即Redo log sequence number
35	FHRBA_BNO NUMBER	Block number，即the redo log file block number
36	FHRBA_BOF NUMBER	Byte offset，the byte offset into the block at which the redo record starts
37	FHETB RAW(132)	enable threads byte，这个我不确定，是猜的。
38	FHCPC NUMBER	CHECKPOINT_COUNT, Datafile checkpoint count
39	FHRTS VARCHAR2(20)	Recoverd timestamp
40	FHCCC NUMBER	Controlfile Checkpoint Count: Saved copy of the control file record of the checkpoint count. Helps detect old control files.
41	FHBCP_SCN VARCHAR2(16)	Backup Checkpoint SCN: Updated with the checkpoint done while file in Hot backup
42	FHBCP_TIM VARCHAR2(20)	Backup Checkpoint TIME: Updated with the checkpoint done while file in Hot backup
43	FHBCP_THR NUMBER	Backup Checkpoint Thread: Updated with the checkpoint done while file in Hot backup
44	FHBCP_RBA_SEQ NUMBER	Backup Checkpoint Sequence, 即Redo log sequence number: Updated with the checkpoint done while file in Hot backup
45	FHBCP_RBA_BNO NUMBER	the redo log file block number, Updated with the checkpoint done while file in Hot backup
46	FHBCP_RBA_BOF NUMBER	Byte offset，the byte offset into the block at which the redo record starts, Updated with the checkpoint done while file in Hot backup
47	FHBCP_ETB RAW(132)	enable threads byte，这个我不确定，是猜的
48	FHBHZ NUMBER	begin hot backup file size
49	FHXCD RAW(16)	External cache id: Used to ensure that concurrent instances access data through consistent external cache
50	FHTSN NUMBER	TS#，Tablespace number
51	FHTNM VARCHAR2(30)	TABLESPACE_NAME, Tablespace name
52	FHRFN NUMBER	RFILE#, Tablespace relative datafile number
53	FHAFS VARCHAR2(16)	absolute fuzzy scn, 即Minimum PITR SCN
54	FHRFS VARCHAR2(16)	The SCN at which the recovery of this file will be complete (no longer fuzzy). Both above fuzzy SCNs must be zero unless a fuzzy flag is set, and must be greater than the checkpoint SCN
55	FHRFT VARCHAR2(20)	The time at which the recovery of this file will be complete (no longer fuzzy).
56	HXIFZ NUMBER	File is fuzzy (YES | NO)，decode(hxifz, 0,’NO’, 1,’YES’, NULL)
57	HXNRCV NUMBER	File needs media recovery (YES | NO)，decode(hxnrcv, 0,’NO’, 1,’YES’,NULL)
58	HXFNM VARCHAR2(513)	NAME, Datafile name
59	FHPOFB NUMBER
60	FHPNFB NUMBER
61	FHPRE10 NUMBER
62	FHFIRSTUNRECSCN VARCHAR2(16)	UNRECOVERABLE_CHANGE#, Last unrecoverable change number made to this datafile. If the database is in ARCHIVELOG mode, then this column is updated when an unrecoverable operation completes. If the database is not in ARCHIVELOG mode, this column does not get updated.
63	FHFIRSTUNRECTIME VARCHAR2(20)	UNRECOVERABLE_TIME, Timestamp of the last unrecoverable change. This column is updated only if the database is in ARCHIVELOG mode.
64	HXLMDBA NUMBER	SPACE_HEADER, The amount of space currently being used and the amount that is free, as identified in the space header. decode(hxlmdba, 0, NULL, hxlmdba)
65	HXLMLD_SCN VARCHAR2(16)	LAST_DEALLOC_SCN, Last deallocated SCN