Server Administration :: How Much Flash Recovery Area Is Enough For Flashback

here's my settings

SYS@boston>SELECT ESTIMATED_FLASHBACK_SIZE FROM V$FLASHBACK_DATABASE_LOG;

ESTIMATED_FLASHBACK_SIZE
------------------------
45195264

SYS@boston>select name, value, issys_modifiable from v$parameter where name='db
_recovery_file_dest_size';

NAME
--------------------------------------------------------------------------------
VALUE
--------------------------------------------------------------------------------
ISSYS_MOD
---------
db_recovery_file_dest_size
9663676416
IMMEDIATE

SYS@boston>select * from v$recovery_file_dest;

NAME
--------------------------------------------------------------------------------
SPACE_LIMIT SPACE_USED SPACE_RECLAIMABLE NUMBER_OF_FILES
----------- ---------- ----------------- ---------------
D:Ora102chicagooston_recover
9663676416 1671241216 1103842304 50

SYS@boston>select * from v$flash_recovery_area_usage;

FILE_TYPE PERCENT_SPACE_USED PERCENT_SPACE_RECLAIMABLE NUMBER_OF_FILES
------------ ------------------ ------------------------- ---------------
CONTROLFILE 0 0 0
ONLINELOG .04 0 1
ARCHIVELOG .16 .01 21
BACKUPPIECE 16.84 11.41 22
IMAGECOPY 0 0 0
FLASHBACKLOG .25 0 6

6 rows selected.

SYS@boston>

I have configured a flash recovery area of 9g yet the system keeps complaining that i have not enough flashback logs?

SPACE_RECLAIMABLE 1103842304
ESTIMATED_FLASHBACK_SIZE 45195264

the space_reclaimable is more than ESTIMATED_FLASHBACK_SIZE, so how is it possible the system always complain not enough space?

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Quote:

SQL> SELECT TO_CHAR(STANDBY_BECAME_PRIMARY_SCN) FROM V$DATABASE;

it returns me 0, I try to flashback the now defunct former primary db chicago, the system complains. so how much is really enough?

from

[URL]......

Quote:
V$FLASHBACK_DATABASE_LOG