1 Diag Cdump /opt/app/oracle/diag/rdbms/rhys/RHYS/cdump
1 Health Monitor /opt/app/oracle/diag/rdbms/rhys/RHYS/hm
1 Default Trace File /opt/app/oracle/diag/rdbms/rhys/RHYS/trace/RHYS_ora_3967.trc
1 Active Problem Count 0
1 Active Incident Count 0
11 rows selected.
SQL>
SQL>
SQL>
SQL>
SQL> exit
Dump of First Level Bitmap Block
--------------------------------
nbits : 4 nranges: 1 parent dba: 0x0140000a poffset: 5
unformatted: 0 total: 4 first useful block: 0
owning instance : 1
instance ownership changed at 12/16/2013 21:06:20
Last successful Search 12/16/2013 21:06:20
Freeness Status: nf1 0 nf2 0 nf3 0 nf4 0
Extent Map Block Offset: 4294967295
First free datablock : 4
Bitmap block lock opcode 0
Locker xid: : 0x0000.000.00000000
Dealloc scn: 925704.0
Flag: 0x00000000 (-/-/-/-/-/-)
Inc #: 0 Objd: 87521
--------------------------------------------------------
DBA Ranges :
--------------------------------------------------------
0x01400040 Length: 4 Offset: 0
0:FULL 1:FULL 2:FULL 3:FULL
--------------------------------------------------------
End dump data blocks tsn: 6 file#: 5 minblk 49 maxblk 49
注意这也是第一个位图块，父指针指向第二个位图块10块，管理4个block，加上48块的位图块管理块，正好是20个块。
注意：刚刚开始在dump第九个块开始，可是在创建表的时候分配的第一个块为第8个块。下面查看一下：
[oracle@oracle-one ~]$ sqlplus / as sysdba
SQL*Plus: Release 11.2.0.4.0 Production on Mon Dec 16 22:24:38 2013
Copyright (c) 1982, 2013, Oracle. All rights reserved.
Connected to:
Oracle Database 11g Enterprise Edition Release 11.2.0.4.0 - 64bit Production
With the Partitioning, Automatic Storage Management, OLAP, Data Mining
and Real Application Testing options
SQL> set linesize 200
SQL> col name for a30
SQL> col value for a70
SQL> alter system dump datafile 5 block 8;
System altered.
SQL> select * from v$diag_info;
INST_ID NAME VALUE
---------- ------------------------------ ----------------------------------------------------------------------
1 Diag Enabled TRUE
1 ADR Base /opt/app/oracle
1 ADR Home /opt/app/oracle/diag/rdbms/rhys/RHYS
1 Diag Trace /opt/app/oracle/diag/rdbms/rhys/RHYS/trace
1 Diag Alert /opt/app/oracle/diag/rdbms/rhys/RHYS/alert
1 Diag Incident /opt/app/oracle/diag/rdbms/rhys/RHYS/incident
1 Diag Cdump /opt/app/oracle/diag/rdbms/rhys/RHYS/cdump
1 Health Monitor /opt/app/oracle/diag/rdbms/rhys/RHYS/hm
1 Default Trace File /opt/app/oracle/diag/rdbms/rhys/RHYS/trace/RHYS_ora_4037.trc
1 Active Problem Count 0
1 Active Incident Count 0
11 rows selected.
SQL> exit
Dump of First Level Bitmap Block
--------------------------------
nbits : 4 nranges: 1 parent dba: 0x0140000a poffset: 0
unformatted: 0 total: 16 first useful block: 4
owning instance : 1
instance ownership changed at 12/16/2013 21:03:15
Last successful Search 12/16/2013 21:03:15
Freeness Status: nf1 0 nf2 0 nf3 0 nf4 0
Extent Map Block Offset: 4294967295
First free datablock : 16
Bitmap block lock opcode 0
Locker xid: : 0x0000.000.00000000
Dealloc scn: 925704.0
Flag: 0x00000000 (-/-/-/-/-/-)
Inc #: 0 Objd: 87521
--------------------------------------------------------
DBA Ranges :
--------------------------------------------------------
0x01400008 Length: 16 Offset: 0
0:Metadata 1:Metadata 2:Metadata 3:Metadata
4:FULL 5:FULL 6:FULL 7:FULL
8:FULL 9:FULL 10:FULL 11:FULL
12:FULL 13:FULL 14:FULL 15:FULL
--------------------------------------------------------
End dump data blocks tsn: 6 file#: 5 minblk 8 maxblk 8
可以看出该块管理16个块前四个包含了元数据信息