Using Oracle Workspaces

Say the thing we can't do with versioning in Oracle. One really useful feature I often use for day to day stuff is workspaces. A workspace is an independent space where you can play with a table (or a whole bunch of tables) before you actually decide you want your new data to be the live data. Inside a workspace you can commit and rollback data without affecting any other workspace. Even though one should always test and prepare any work on a staging system it can be reassuring not to actually modify a live table without knowing how it will look. You can have almost unlimited numbers of workspaces and even have child workspaces to a parent. You can even do DDL operations. The workspace for the live data is simply called LIVE (in caps).
Let's do a little test.

-- Lets begin with enabling versioning 
-- and creating the new workspace
HALI@spinner1> exec dbms_wm.enableversioning('t1');

PL/SQL procedure successfully completed.

HALI@spinner1> exec dbms_wm.createworkspace('test');

PL/SQL procedure successfully completed.

-- Don't forget to actually switch to your new ws
HALI@spinner1> exec dbms_wm.gotoworkspace('test');

PL/SQL procedure successfully completed.

HALI@spinner1> select * from t1;

        ID NAME
---------- ----------
         1 test
         2 test2

-- Ok, lets update the table and insert a new row
OPS$HLINDEN@spinner1> insert into t1(id,name) values(3,'test 3');

1 row created.

OPS$HLINDEN@spinner1> update t1 set name='test 2' where id=2;

1 row updated.

-- Note that we actually commit the data.
OPS$HLINDEN@spinner1> commit;

Commit complete.

HALI@spinner1> select * from t1;

        ID NAME
---------- ----------
         1 test
         2 test 2
         3 test 3

-- Now we switch bake to the LIVE data.
HALI@spinner1> exec dbms_wm.gotoworkspace('LIVE');

PL/SQL procedure successfully completed.

-- And the live data is unchanged at this point.
HALI@spinner1> select * from t1;

        ID NAME
---------- ----------
         1 test
         2 test2

-- But we are happy with our updated data and want
-- our changed to be the added to the live workspace.
HALI@spinner1> exec dbms_wm.mergetable('test','t1');

PL/SQL procedure successfully completed.

HALI@spinner1> select * from t1;

        ID NAME
---------- ----------
         1 test
         2 test 2
         3 test 3

-- Don't forget to clean up after the operation.
HALI@spinner1> exec dbms_wm.removeworkspace('test');

PL/SQL procedure successfully completed.

HALI@spinner1> exec dbms_wm.disableversioning('t1');

PL/SQL procedure successfully completed.

Read the Oracle documentation for workspaces.