测试使用块跟踪文件

生产环境Oracle 11g 数据库全备是4小时，增量备份需要2小时？？？ 那么如何加快周一至周六的增量备份速度，减少备份时间呢？

使用Oracle 块跟踪，开启后，备份时跳过无需备份的信息，只需要根据块跟踪文件记录改变了的blocks进行备份，加快备份扫描的速度！

从如下测试可以发现测试环境

 全库备份826Mb需要4分钟时间，增量1级差异备份需要2分钟？？？如果启用块跟踪后，增量1级差异备份只需要5s当时是没有数据，真实时间速度也很快。

http://blog.itpub.net/31397003/viewspace-2636387/  差异与累计备份区别参考链接

SQL> select sum(bytes)/1024/1024/1024 from dba_segments;
SUM(BYTES)/1024/1024/1024
-------------------------
               1.68725586
alter session set nls_date_format='YYYY-MM-DD:HH24:MI:SS';
backup as compressed backupset database include current controlfile format '/bak/FULLBAK_%U_%d_%s_not.bak';
Starting backup at 2020-05-07 05:04:01
Finished Control File and SPFILE Autobackup at 2020-05-07 05:08:36  
826Mb =>4Min:35s

由于全备无法作为增量备份使用！需要重新进行数据库全备
backup incremental level 0 as compressed backupset database format '/bak/full_%d_%T_%t_%s_%p';
Starting backup at 2020-05-07 05:09:33
Finished Control File and SPFILE Autobackup at 2020-05-07 05:12:42
824Mb=>3Min:10s


backup incremental level 1 as compressed backupset database format '/bak/full_%d_%T_%t_%s_%p';
Starting backup at 2020-05-07 05:13:38
Finished Control File and SPFILE Autobackup at 2020-05-07 05:15:21
1Mb=>2min

==
SQL> alter database enable block change tracking using file '+DATA' reuse;
SQL> select status,filename from v$block_change_tracking;
STATUS     FILENAME
---------- -----------------------------------------------------------------
ENABLED    +DATA/ORCL/CHANGETRACKING/ctf.324.1039756611

RMAN> alter session set nls_date_format='YYYY-MM-DD:HH24:MI:SS';
RMAN> backup incremental level 0 as compressed backupset database format '/bak/full_%d_%T_%t_%s_%p';
Starting backup at 2020-05-07 05:18:31
Finished Control File and SPFILE Autobackup at 2020-05-07 05:22:20
825Mb=>4Min

RMAN> backup incremental level 1 as compressed backupset database format '/bak/full_%d_%T_%t_%s_%p';
Starting backup at 2020-05-07 05:27:14
Finished Control File and SPFILE Autobackup at 2020-05-07 05:27:19
1Mb=>5s