oracle数据文件内部BLOCK结构详解

datafile block block size :8192

10.1.0~lgone@ONE.LG.OK> create table a(v varchar2(4000)) TABLESPACE t;

Table created.

10.1.0~lgone@ONE.LG.OK> insert into a values('a');

1 row created.


Start dump data blocks tsn: 17 file#: 5 minblk 10 maxblk 10
buffer tsn: 17 rdba: 0x0140000a (5/10)   
   //// buffer tsn:        
         数据文件对应的 tablespace 的 number   这只是dump文件中记录的数据而已
         block 中是没有记录 tablespace 的 number 的  

scn: 0x0000.0043890e seq: 0x05 flg: 0x02 tail: 0x890e0605
frmt: 0x02 chkval: 0x0000 type: 0x06=trans data
Block header dump:  0x0140000a
 Object id on Block? Y
 seg/obj: 0xd254  csc: 0x00.43890a  itc: 2  flg: O  typ: 1 - DATA
     fsl: 0  fnx: 0x0 ver: 0x01
 
 Itl           Xid                  Uba         Flag  Lck        Scn/Fsc
0x01   0x0004.00c.00001850  0x00801496.07b9.01  --U-    1  fsc 0x0000.0043890e
0x02   0x0000.000.00000000  0x00000000.0000.00  ----    0  fsc 0x0000.00000000
 
data_block_dump,data header at 0x87e125c
   ////  data_block_dump,data header at 0x87e125c
         其实这个block不是直接从 data buffer 中 dump 出来的这个表示真正dump时 block 的数据区的起始位置
         也就是下面这部分开始的位置
         
===============        ////  tsiz:    hsiz:   pbl:   bdba: 在数据文件都是没有存储的 
tsiz: 0x1fa0           //// Total data area size  
                     8k的block: 8192-20(block head)-24(Transaction Header)-24*2(一个事务条)-4(block tail)=8096(0x1fa0)
hsiz: 0x14             //// Data header size  数据块头20个字节+数据块尾4个字节=24字节(0x14)
pbl: 0x087e125c        //// Pointer to buffer holding the block
bdba: 0x0140000a
     76543210
   
flag=--------
ntab=1
nrow=1
frre=-1
fsbo=0x14
fseo=0x1f9b
avsp=0x1f83
tosp=0x1f83
0xe:pti[0]  nrow=1  offs=0
0x12:pri[0] offs=0x1f9b
block_row_dump:
tab 0, row 0, @0x1f9b
tl: 5 fb: --H-FL-- lb: 0x1  cc: 1
col  0: [ 1]  61
end_of_block_dump
End dump data blocks tsn: 17 file#: 5 minblk 10 maxblk 10

block 坏掉了还可以报:
    ORA-600 (4519) Cache layer block type is incorrect
    ORA-600 (4393) Check for Type for Segment header with free list
    ORA-600 (4136) Check Rollback segment block
    ORA-600 (4154) Check Rollback segment block 

    Ora-600[kcbzpb_1],[d],[kind],[chk] gets signaled when the block got corrupted in memory.
    The only way it should be bad is if a stray store into memory destroyed the header or tail.
    d = blocknumber, kind= kind of corruption detected,chk = checksum flag

    ora-600[3398] and ora-600[3339]  
    ora-600[3398] is not in oracle 8.
    ora-600[3398] means it failed a verification check before writing back to disk,  so it must 
        be an in-memory corruption.
    ora-600[3339] comes with ora-1578 and means either disk corruption or in memory corruption after read.
    ora-600 [3339] has been removed from 7.2+
    From 7.2+  ora-600 [3398] has become ora-600 [3374] with some checks added.

2进制存储格式
               ALTER SESSION SET EVENTS '10289 trace name context forever, level 1';
               ALTER SESSION SET EVENTS '10289 trace name context off';