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