Oracle 26ai: Flashback Database Logs Outside the Fast Recovery Area

From Oracle database 23ai/26ai, flashback logs can be stored outside the fast recovery area. This allows us to place flashback database logs on different storage, and means they are not competing for space with the rest of the contents of the fast recovery area.

First we need a directory to place logs:

[oracle@olinux8 ~]$ mkdir -p /u01/flashback_logs

Set destination and size at db:

SQL> alter system set db_flashback_log_dest_size=10g;
System altered.
SQL> alter system set db_flashback_log_dest='/u01/flashback_logs';
System altered.
SQL>

Enable flashback if not already:

SQL> alter database flashback on;
Database altered.

Now, notice after setting it up separate from FRA, v$recovery_area_usage does not list Flashback logs:

BEFORE:

SQL>  select FILE_TYPE, PERCENT_SPACE_USED as "% used",PERCENT_SPACE_RECLAIMABLE as "% reclaimable",  NUMBER_OF_FILES from v$flash_recovery_area_usage;
FILE_TYPE                   % used % reclaimable NUMBER_OF_FILES
----------------------- ---------- ------------- ---------------
CONTROL FILE                     0             0               0
REDO LOG                         0             0               0
ARCHIVED LOG                     0             0               1
BACKUP PIECE                     0             0               0
IMAGE COPY                       0             0               0
FLASHBACK LOG                    0             0               0
FOREIGN ARCHIVED LOG             0             0               0
AUXILIARY DATAFILE COPY          0             0               0

8 rows selected.


AFTER:

SQL> select FILE_TYPE, PERCENT_SPACE_USED as "% used",PERCENT_SPACE_RECLAIMABLE as "% reclaimable",  NUMBER_OF_FILES from v$flash_recovery_area_usage;
FILE_TYPE                   % used % reclaimable NUMBER_OF_FILES
----------------------- ---------- ------------- ---------------
CONTROL FILE                     0             0               0
REDO LOG                         0             0               0
ARCHIVED LOG                     0             0               1
BACKUP PIECE                   .09             0               1
IMAGE COPY                       0             0               0
FOREIGN ARCHIVED LOG             0             0               0
AUXILIARY DATAFILE COPY          0             0               0

7 rows selected.

SQL>

Some monitoring views….

monitor the size and location of these new separate logs:

col NAME format a60
set linesize 190
alter session set nls_date_format="DD-MON-YYYY HH24:MI:SS";
select * from V$FLASHBACK_DATABASE_LOGFILE;


NAME                                                               LOG#    THREAD#  SEQUENCE#      BYTES FIRST_CHANGE# FIRST_TIME           TYPE          CON_ID
------------------------------------------------------------ ---------- ---------- ---------- ---------- ------------- -------------------- --------- ----------
/u01/flashback_logs/DBTEST26/flashback/o1_mf_nsjnyfwn_.flb            1          1          1  209715200       3334509 20-FEB-2026 12:30:13 NORMAL             0
/u01/flashback_logs/DBTEST26/flashback/o1_mf_nsjnyqxp_.flb            2          1          1  209715200             0                      RESERVED           0


Check total flashback data generated: 

SQL> SELECT * FROM v$flashback_database_stat;

BEGIN_TIME           END_TIME             FLASHBACK_DATA    DB_DATA  REDO_DATA ESTIMATED_FLASHBACK_SIZE     CON_ID
-------------------- -------------------- -------------- ---------- ---------- ------------------------ ----------
20-FEB-2026 12:30:14 20-FEB-2026 12:52:18        1720320    2564096    2012672                        0          0

Now, I could not find an specific view that provides a similar output than v$flash_recovery_area_usage to monitor usage (please write it down if you find some….) so we can run this query to monitor usage:

WITH param AS (
  SELECT LOWER(value) val
  FROM   v$parameter
  WHERE  name = 'db_flashback_log_dest_size'
),
dest_bytes AS (
  SELECT CASE
           WHEN val IS NULL THEN NULL
           WHEN val = '0' THEN NULL                -- 0 means "no limit" for some setups; treat as NULL
           WHEN REGEXP_LIKE(val,'^[0-9]+(\.[0-9]+)?g$') THEN TO_NUMBER(REGEXP_REPLACE(val,'[^0-9.]')) * POWER(1024,3)
           WHEN REGEXP_LIKE(val,'^[0-9]+(\.[0-9]+)?m$') THEN TO_NUMBER(REGEXP_REPLACE(val,'[^0-9.]')) * POWER(1024,2)
           WHEN REGEXP_LIKE(val,'^[0-9]+(\.[0-9]+)?k$') THEN TO_NUMBER(REGEXP_REPLACE(val,'[^0-9.]')) * 1024
           WHEN REGEXP_LIKE(val,'^[0-9]+(\.[0-9]+)?b$') THEN TO_NUMBER(REGEXP_REPLACE(val,'[^0-9.]'))
           WHEN REGEXP_LIKE(val,'^[0-9]+(\.[0-9]+)?$')  THEN TO_NUMBER(val)   -- numeric bytes
           ELSE NULL
         END AS dest_bytes
  FROM param
)
SELECT
  ROUND(NVL(s.used_bytes,0) / 1024 / 1024,2) used_mb,
  ROUND(d.dest_bytes / 1024 / 1024,2) dest_mb,
  CASE WHEN d.dest_bytes IS NULL THEN NULL
       WHEN d.dest_bytes = 0 THEN NULL
       ELSE ROUND( NVL(s.used_bytes,0) / d.dest_bytes * 100, 2 )
  END percent_used
FROM
  ( SELECT NVL(SUM(bytes),0) used_bytes FROM v$flashback_database_logfile WHERE type='NORMAL' ) s,
  dest_bytes d;
  
  
   USED_MB    DEST_MB PERCENT_USED
---------- ---------- ------------
       200      10240         1.95

That’s it!