[bbk4485]第二章Flashback Database 04

Monitoring Flashback Database

To monitor the ability to meet your retention target:

• View the Fast Recovery Area disk quota:

SQL> select estimated_flashback_size,flashback_size FROM V$FLASHBACK_DATABASE_LOG;

ESTIMATED_FLASHBACK_SIZE FLASHBACK_SIZE
------------------------ --------------
               236912640       63766528

根据实际运行情况，估算磁盘配额比例

• Determine the current flashback window

SQL> SELECT oldest_flashback_scn,oldest_flashback_time FROM V$FLASHBACK_DATABASE_LOG;

OLDEST_FLASHBACK_SCN OLDEST_FLASHBACK_T
-------------------- ------------------
             4284553 15-MAY-13

最早能闪回到哪个点？时间点、SCN;

• Monitor logging in the Flashback Database logs:

SQL> SELECT * FROM V$FLASHBACK_DATABASE_STAT;

BEGIN_TIME         END_TIME           FLASHBACK_DATA    DB_DATA  REDO_DATA ESTIMATED_FLASHBACK_SIZE
------------------ ------------------ -------------- ---------- ---------- ------------------------
15-MAY-13          15-MAY-13                32456704   39747584   31642112                        0
15-MAY-13          15-MAY-13                 3506176    4407296    1249792                101498880
15-MAY-13          15-MAY-13                 3481600    4399104    1229824                106487808
15-MAY-13          15-MAY-13                 8298496   11722752    2757632                115752960

V$FLASH_RECOVERY_AREA_USAGE

You can query V$FLASH_RECOVERY_AREA_USAGE to view the flash recovery area disk space usage.

SQL> SELECT file_type,percent_space_used AS used,percent_space_reclaimable AS reclaimable,number_of_files AS "number" FROM V$FLASH_RECOVERY_AREA_USAGE;

FILE_TYPE                  USED RECLAIMABLE     number
-------------------- ---------- ----------- ----------
CONTROL FILE                  0           0          0
REDO LOG                      0           0          0
ARCHIVED LOG              62.72           0        188
BACKUP PIECE              11.37           0          2
IMAGE COPY                    0           0          0
FLASHBACK LOG               .59           0          4
FOREIGN ARCHIVED LOG          0           0          0

7 rows selected.