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BBED> map /v
File: /opt/oracle/oradata/xifenfei/xff01.dbf (2)
Block: 530 Dba:0x00800212
------------------------------------------------------------
KTB Data Block (Table/Cluster)
struct kcbh, 20 bytes @0
ub1 type_kcbh @0
ub1 frmt_kcbh @1
ub1 spare1_kcbh @2
ub1 spare2_kcbh @3
ub4 rdba_kcbh @4
ub4 bas_kcbh @8
ub2 wrp_kcbh @12
ub1 seq_kcbh @14
ub1 flg_kcbh @15
ub2 chkval_kcbh @16
ub2 spare3_kcbh @18
struct ktbbh, 72 bytes @20
ub1 ktbbhtyp @20
union ktbbhsid, 4 bytes @24
struct ktbbhcsc, 8 bytes @28
b2 ktbbhict @36
ub1 ktbbhflg @38
ub1 ktbbhfsl @39
ub4 ktbbhfnx @40
struct ktbbhitl[2], 48 bytes @44
struct kdbh, 14 bytes @92
ub1 kdbhflag @92
b1 kdbhntab @93
b2 kdbhnrow @94
sb2 kdbhfrre @96
sb2 kdbhfsbo @98
sb2 kdbhfseo @100
b2 kdbhavsp @102
b2 kdbhtosp @104
struct kdbt[1], 4 bytes @106
b2 kdbtoffs @106
b2 kdbtnrow @108
sb2 kdbr[101] @110
ub1 freespace[4270] @312
ub1 rowdata[3606] @4582
ub4 tailchk @8188
BBED>
////////////////////////////////////////////////////////////////////////////////////////
//////////// Block Header Structure, 20 bytes//////////////////////////////////////////
BBED> p kcbh
struct kcbh, 20 bytes @0
ub1 type_kcbh @0 -- Block Type
-- 01 - Undo segment header
-- 02 - Undo data block
-- 03 - Save undo header
-- 04 - Save undo data block
-- 05 - Data segment header
-- 06 - Trans data, KTB managed data block(with ITL)
-- 07 - Temp table data block (no ITL)
-- 08 - Sort key
-- 09 - Sort Run
-- 10 - Segment free list block
-- 11 - Data file header
ub1 frmt_kcbh @1 -- Block Format 1=Oracle7, 2=Oracle8+
ub1 spare1_kcbh @2 -- Not used, filler field
ub1 spare2_kcbh @3 -- Not used, filler field
ub4 rdba_kcbh @4 -- RDBA (4 bytes) - Relative Data Block Address
ub4 bas_kcbh @8 -- SCN Base (4 bytes)
ub2 wrp_kcbh @12 -- SCN Wrap (2 bytes)
ub1 seq_kcbh @14 -- Sequence Number, incremented for every change made to the block at the same SCN
ub1 flg_kcbh @15 -- Flag:
-- 0x01 New Block
-- 0x02 Delayed Logging Chang advanced SCN/seq
-- 0x04 Check value saved - block XOR's to Zero
-- 0x08 Temporary block
ub2 chkval_kcbh @16 -- Optional block checksum (if DB_BLOCK_CHECKSUM=TRUE)
ub2 spare3_kcbh @18 -- Not used, filler field
/////////////////////////////////////////////////////////////////////////////////////////
/////////Transaction Fixed Header Structure, 72 Bytes////////////////////////////////////
BBED> p ktbbh
struct ktbbh, 72 bytes @20
ub1 ktbbhtyp @20 -- Block type (1=DATA, 2=INDEX)
union ktbbhsid, 4 bytes @24 -- Segment/Object ID
struct ktbbhcsc, 8 bytes @28 -- SCN at last block cleanout
b2 ktbbhict @36 -- Number of ITL slots
ub1 ktbbhflg @38 -- 0=on the freelist
ub1 ktbbhfsl @39 -- ITL TX freelist slot
ub4 ktbbhfnx @40 -- DBA of next block on the freelist
struct ktbbhitl[2], 48 bytes @44 -- ITL list index, each ITL takes up 24 bytes
//////////////////////////////////////////////////////////////////////////////////////////
///////////////Data Header Structure, 14 bytes////////////////////////////////////////////
BBED> p kdbh
struct kdbh, 14 bytes @100
ub1 kdbhflag @100 -- N=pctfree hit(clusters)
-- F=do not put on freelist
-- K=flushable cluster keys
b1 kdbhntab @101 -- Number of tables (>1 in clusters)
b2 kdbhnrow @102 -- Number of rows (2 bytes)
sb2 kdbhfrre @104 -- First free row entry index; -1=you have to add one
sb2 kdbhfsbo @106 -- Freespace begin offset
sb2 kdbhfseo @108 -- Freespace end offset
b2 kdbhavsp @110 -- Available space in the block
b2 kdbhtosp @112 -- Total available space when all TXs commit
////////////////////////////////////////////////////////////////////////////////////////
/////////////////////Table Directory Entry Structure, 4 bytes///////////////////////////
BBED> p kdbt
struct kdbt[1], 4 bytes @114
b2 kdbtoffs @114
b2 kdbtnrow @116
////////////////////////////////////////////////////////////////////////////////////////
////////////////// Row Directory ///////////////////////////////////////////////////////
BBED> p kdbr[100]
sb2 kdbr[100] @310
////////////////////////////////////////////////////////////////////////////////////////
///////////////// Free Space ///////////////////////////////////////////////////////////
BBED> p freespace[4269]
ub1 freespace[4269] @4581
///////////////////////////////////////////////////////////////////////////////////////
/////////////////////Row Data//////////////////////////////////////////////////////////
BBED> p rowdata[3605]
ub1 rowdata[3605] @8187 0x00
//////////////////////////////////////////////////////////////////////////////////////
/////////////////////Block Tail Check, 4 bytes////////////////////////////////////////
BBED> p tailchk
ub4 tailchk @8188 0x24500601
说明事宜：
1、tailchk=Lower order two bytes of SCN Base(bas_kcbh) + Block Type(type_kcbh) + SCN Seq(seq_kcbh)
2、块的scn为：scn=wrp_kcbh+bas_kcbh
求scn语句：select to_char(to_number(‘scn’,’xxxxxxxxxx’),’999999999999′) from dual;
3、dba求文件号，块号为：
set serveroutput on
declare
p_dba VARCHAR2 (255) :='0x00800212';
l_str VARCHAR2 (255) DEFAULT NULL;
BEGIN
l_str :=
'datafile# is:'
|| DBMS_UTILITY.data_block_address_file (TO_NUMBER (LTRIM (p_dba, '0x'),'xxxxxxxx'))
|| chr(10)||'datablock is:'
|| DBMS_UTILITY.data_block_address_block (TO_NUMBER (LTRIM (p_dba, '0x'),'xxxxxxxx'));
dbms_output.put_line(l_str);
END;
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