Flashback Data Archive feature is part of Oracle Total Recall technology. Flashback Data Archive feature lets you to track changes made in any number of tables for any given retention time. The retention time can be some days or months or years.
Flashback data archives retain historical data for the time duration specified using the RETENTION parameter. Historical data can be queried using the Flashback Query AS OF clause. Archived historic data that has aged beyond the specified retention period is automatically purged.
This feature is supported only Oracle 11g Enterprise Edition. It is not available in Standard or Express editions.
Lets see an example.
SQL> create tablespace FB_Storage datafile
size 100m autoextend on segment space management auto;
SQL> create flashback archive default FB_Arch1
tablespace FB_Storage quota 1g retention 1 year
Flashback archive created
For Example to enable flashback archive for table Scott.emp
(i) Grant Flashback archive privilege
SQL> grant flashback archive on fb_arch1 to scott;
SQL> connect scott/tiger
(ii) Enable flashback archive for table
SQL> alter table emp flashback archive
Suppose a user has deleted rows from emp by giving a delete statement like this
SQL> set time on;
21:48:40 SQL> delete from emp where deptno=10;
3 rows deleted.
21:51:38 SQL> commit;
21:57:08 SQL> select * from emp as of timestamp sysdate - 10 / (24*60);
Versions Query (11gR2 only) (To see what changes are made to Emp No. 7902 between last 15 minutes
22:18:34 SQL> select * from emp versions between
timestamp sysdate- 15 /(24*60) and sysdate