Oracle 10g的block change tracking 特性

Block chage tracking是Oracle10g的一个新特性，Block change tracking进程记录自从上一次备份以来数据块的变化，并把这些信息记录在跟踪文件中。RMAN使用这个文件判断增量备份中需要备份的变更数据。这极大的促进了备份性能，RMAN可以不再扫描整个文件以查找变更数据。
启用跟踪可以使用如下命令:

alter database enable block change tracking using file '/data5/flash_recovery_area/EYGLE/eygle_block_track.log';

判断当前设置可以查询:

select filename,status,bytes from v$block_change_tracking;

关闭跟踪:

alter database disable block change tracking;

以下步骤供参考:

SYS AS SYSDBA on 29-MAR-05 >alter database enable block change tracking using 2 file '/data5/flash_recovery_area/EYGLE/eygle_block_track.log'; Database altered. SYS AS SYSDBA on 29-MAR-05 >select filename,status,bytes from v$block_change_tracking; FILENAME -------------------------------------------------------------------------------- STATUS BYTES ---------- ---------- /data5/flash_recovery_area/EYGLE/eygle_block_track.log ENABLED 11599872 SYS AS SYSDBA on 29-MAR-05 >alter database disable block change tracking; Database altered. SYS AS SYSDBA on 29-MAR-05 >select filename,status,bytes from v$block_change_tracking; FILENAME -------------------------------------------------------------------------------- STATUS BYTES ---------- ---------- DISABLED