alter database flashback on;

To throw a random silly change into your JOBS table:

update jobs j set job_title = ( select job_title from random_job ) where job_id = ( select job_id from random_job );

Tasks

Query the values of JOBS a few minutes ago.

SELECT * FROM jobs AS OF TIMESTAMP SYSDATE - 0.01;

Find out what SCN the database is at now: 
SELECT current_scn FROM v$database;

Query the values of JOBS a few transactions ago, using SCNs.

Flashback Table To SCN xxxxxx

Flashback Table (tablename) To Before Drop

Investigate user_recyclebin; purge recyclebin;

Oracle Enterprise Manager is being served at https://l172.16.33.1:5500/em

Version of flatxn_setup1 for your own schema:

flatxn_setup1.sql

REM "******************************************* "

REM "For demo purposes ONLY:"

REM "  * Setup for Flashback Transaction"

REM "Execute script as SYSDBA" 

set echo on

set serveroutput on

set term on

set lines 200

set pause on

/*== Set up the &&username database account for this OBE ==*/

ALTER DATABASE ADD SUPPLEMENTAL LOG DATA;

ALTER DATABASE ADD SUPPLEMENTAL LOG DATA (PRIMARY KEY) COLUMNS;

GRANT EXECUTE ON dbms_flashback TO &&username;

GRANT select any transaction TO &&username;

pause Press [Enter] to continue...

/*== Create test data for flashback transaction ==*/

connect &&username/&&username

/*== Test transaction 1 ==*/

INSERT INTO &&username.regions VALUES (10,'Pole');

INSERT INTO &&username.regions VALUES (20,'Moon');

INSERT INTO &&username.regions VALUES (30,'Venus');

INSERT INTO &&username.regions VALUES (40,'Mars');

INSERT INTO &&username.regions VALUES (50,'Saturn');

COMMIT;

pause Press [Enter] to continue...

/*== Test transaction 2 ==*/

/*== Region 10 and 20 has a WAW dependency on transaction 1 ==*/

UPDATE &&username.regions SET region_name='Two Poles'  WHERE region_id = 10;

UPDATE &&username.regions SET region_name='Many Moons' WHERE region_id = 20;

COMMIT;

pause Press [Enter] to continue...

/*== Test transaction 3 ==*/

/*== Region 10 has a WAW dependency on transaction 1 and 2 ==*/

/*== Region 40 and 50 has a WAW dependency on transaction 1 ==*/

UPDATE &&username.regions SET region_name='No star'  WHERE region_id = 10;

UPDATE &&username.regions SET region_name='Red star' WHERE region_id = 40;

UPDATE &&username.regions SET region_name='Big star' WHERE region_id = 50;

COMMIT;

pause Press [Enter] to continue...

/*== Test transaction 4 ==*/

/*== Region 30 has a WAW dependency on transaction 1 ==*/

UPDATE &&username.regions SET region_name='Still called Venus' WHERE region_id = 30;

COMMIT;

pause Press [Enter] to continue...

connect / as sysdba

ALTER SYSTEM ARCHIVE LOG CURRENT;

prompt "Setup for Flashback Transaction completed"

pause Press [Enter] to continue...

exit