从10G版本开始，引入了BLOCK CHANGE TRACKING特性，这次算是真正的增量了。
当这个特性开启后，ORACLE会创建一个trace文件，并起用后台进程CTWR记录变化的数据块，当需要增量备份的时候，就直接读这个文件获得要备份的数据块，速度确实是有质的飞跃（参考http://www.alidba.net/index.php/archives/51）
--启用BLOCK CHANGE TRACKING特性
SQL> alter database enable block change tracking using file '/data/ora10g/RACDBSTD/trace.dbf' reuse;
Database altered.
SQL> shutdown immediate
Database closed.
Database dismounted.
ORACLE instance shut down.
SQL> startup
ORACLE instance started.
Total System Global Area 167772160 bytes
Fixed Size 1218316 bytes
Variable Size 62916852 bytes
Database Buffers 100663296 bytes
Redo Buffers 2973696 bytes
Database mounted.
Database opened.
--全备数据库（这个全备好像需要再开启BLOCK CHANGE TRACKING后，后面的增备才能利用到）
RMAN> run{
2> allocate channel c1 device type disk format '/data/backup/db_fullb%u';
3> backup incremental level 0 database ;
4> }
released channel: ORA_DISK_1
allocated channel: c1
channel c1: sid=141 devtype=DISK
Starting backup at 14-MAY-11
channel c1: starting incremental level 0 datafile backupset
channel c1: specifying datafile(s) in backupset
input datafile fno=00001 name=/data/ora10g/RACDBSTD/system.259.727735501
input datafile fno=00003 name=/data/ora10g/RACDBSTD/sysaux.261.727735559
input datafile fno=00002 name=/data/ora10g/RACDBSTD/undo01.DBF
input datafile fno=00005 name=/data/ora10g/RACDBSTD/users.264.727735605
channel c1: starting piece 1 at 14-MAY-11
channel c1: finished piece 1 at 14-MAY-11
piece handle=/data/backup/db_fullb17mcb0h7 tag=TAG20110514T182335 comment=NONE
channel c1: backup set complete, elapsed time: 00:00:45
channel c1: starting incremental level 0 datafile backupset
channel c1: specifying datafile(s) in backupset
including current control file in backupset
channel c1: starting piece 1 at 14-MAY-11
channel c1: finished piece 1 at 14-MAY-11
piece handle=/data/backup/db_fullb18mcb0ik tag=TAG20110514T182335 comment=NONE
channel c1: backup set complete, elapsed time: 00:00:02
Finished backup at 14-MAY-11
released channel: c1
--增量备份
SQL> drop table testtab purge;
Table dropped.
SQL> create table testtab as select * from dba_objects where 1 = 2;
Table created.
SQL> insert into testtab select * from dba_objects;
44964 rows created.
SQL> commit;
Commit complete.
RMAN> run{
2> allocate channel c1 device type disk format '/data/backup/db_incb%u';
3> backup incremental level 1 database ;
4> };
allocated channel: c1
channel c1: sid=141 devtype=DISK
Starting backup at 14-MAY-11
channel c1: starting incremental level 1 datafile backupset
channel c1: specifying datafile(s) in backupset
input datafile fno=00001 name=/data/ora10g/RACDBSTD/system.259.727735501
input datafile fno=00003 name=/data/ora10g/RACDBSTD/sysaux.261.727735559
input datafile fno=00002 name=/data/ora10g/RACDBSTD/undo01.DBF
input datafile fno=00005 name=/data/ora10g/RACDBSTD/users.264.727735605
channel c1: starting piece 1 at 14-MAY-11
channel c1: finished piece 1 at 14-MAY-11
piece handle=/data/backup/db_incb19mcb0k0 tag=TAG20110514T182503 comment=NONE
channel c1: backup set complete, elapsed time: 00:00:07
channel c1: starting incremental level 1 datafile backupset
channel c1: specifying datafile(s) in backupset
including current control file in backupset
channel c1: starting piece 1 at 14-MAY-11
channel c1: finished piece 1 at 14-MAY-11
piece handle=/data/backup/db_incb1amcb0k7 tag=TAG20110514T182503 comment=NONE
channel c1: backup set complete, elapsed time: 00:00:02
Finished backup at 14-MAY-11
released channel: c1
SQL> alter session set nls_date_format='yyyy-mm-dd hh24:mi:ss';
Session altered.
SQL> select file#, incremental_level, completion_time, datafile_blocks ,blocks_read,
2 trunc((blocks_read / datafile_blocks) * 100,2) as "read%",
3 used_change_tracking
4 from v$backup_datafile
5 where incremental_level > 0
6 order by completion_time;
FILE# INCREMENTAL_LEVEL COMPLETION_TIME DATAFILE_BLOCKS BLOCKS_READ read% USE
---------- ----------------- ------------------- --------------- ----------- ---------- ---
5 1 2011-05-14 18:10:51 640 640 100 NO
2 1 2011-05-14 18:10:58 6400 6400 100 NO
3 1 2011-05-14 18:11:08 20480 20480 100 NO
1 1 2011-05-14 18:11:17 53760 53760 100 NO
5 1 2011-05-14 18:15:51 640 640 100 NO
2 1 2011-05-14 18:15:58 6400 6400 100 NO
3 1 2011-05-14 18:16:08 20480 20480 100 NO
1 1 2011-05-14 18:16:18 53760 53760 100 NO
3 1 2011-05-14 18:17:25 20480 1 0 YES
1 1 2011-05-14 18:17:25 53760 1 0 YES
2 1 2011-05-14 18:17:25 6400 1 .01 YES
FILE# INCREMENTAL_LEVEL COMPLETION_TIME DATAFILE_BLOCKS BLOCKS_READ read% USE
---------- ----------------- ------------------- --------------- ----------- ---------- ---
5 1 2011-05-14 18:17:25 640 1 .15 YES
1 1 2011-05-14 18:25:07 53760 679 1.26 YES
3 1 2011-05-14 18:25:07 20480 2039 9.95 YES
2 1 2011-05-14 18:25:07 6400 419 6.54 YES
5 1 2011-05-14 18:25:07 640 1 .15 YES
16 rows selected.
SQL> shutdown abort
ORACLE instance shut down.
--删除数据文件
rm /data/ora10g/RACDBSTD/users.264.727735605
--恢复
RMAN> startup mount
Oracle instance started
database mounted
Total System Global Area 167772160 bytes
Fixed Size 1218316 bytes
Variable Size 62916852 bytes
Database Buffers 100663296 bytes
Redo Buffers 2973696 bytes
RMAN> restore database;
Starting restore at 14-MAY-11
using target database control file instead of recovery catalog
allocated channel: ORA_DISK_1
channel ORA_DISK_1: sid=157 devtype=DISK
channel ORA_DISK_1: starting datafile backupset restore
channel ORA_DISK_1: specifying datafile(s) to restore from backup set
restoring datafile 00001 to /data/ora10g/RACDBSTD/system.259.727735501
restoring datafile 00002 to /data/ora10g/RACDBSTD/undo01.DBF
restoring datafile 00003 to /data/ora10g/RACDBSTD/sysaux.261.727735559
restoring datafile 00005 to /data/ora10g/RACDBSTD/users.264.727735605
channel ORA_DISK_1: reading from backup piece /data/backup/db_fullb17mcb0h7
channel ORA_DISK_1: restored backup piece 1
piece handle=/data/backup/db_fullb17mcb0h7 tag=TAG20110514T182335
channel ORA_DISK_1: restore complete, elapsed time: 00:00:46
Finished restore at 14-MAY-11
--recover 用到了增量备份
RMAN> recover database;
Starting recover at 14-MAY-11
using channel ORA_DISK_1
channel ORA_DISK_1: starting incremental datafile backupset restore
channel ORA_DISK_1: specifying datafile(s) to restore from backup set
destination for restore of datafile 00001: /data/ora10g/RACDBSTD/system.259.727735501
destination for restore of datafile 00002: /data/ora10g/RACDBSTD/undo01.DBF
destination for restore of datafile 00003: /data/ora10g/RACDBSTD/sysaux.261.727735559
destination for restore of datafile 00005: /data/ora10g/RACDBSTD/users.264.727735605
channel ORA_DISK_1: reading from backup piece /data/backup/db_incb19mcb0k0
channel ORA_DISK_1: restored backup piece 1
piece handle=/data/backup/db_incb19mcb0k0 tag=TAG20110514T182503
channel ORA_DISK_1: restore complete, elapsed time: 00:00:03
starting media recovery
media recovery complete, elapsed time: 00:00:05
Finished recover at 14-MAY-11
RMAN> alter database open;
database opened
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