Recovering control file

We can not start the database with out a control file, then how?
We can recover it as below:

-->connect to rman target
-->set dbid
-->startup nomount;
-->restore control file from autobackup;
-->alter database mount;
-->recover database;
-->Alter database open resetlogs;
(some times we face datafile errors while performing resetlogs)
Thats it..
Please take new complete backup again.
Alway keep controlfile autobackup ON

Thanks!

Shrink tablespace from removed data

Some times we wanted remove the data due to less space on tablespace, in that case we need to shrink the tables which we removed and it can be done like below:

Here i am removing data from a table:

SQL> delete from emp where emp_id>100;

100000 rows deleted

now enable the row movement on the particular table.

SQL> alter table emp enable row movement;

table altered

Now shrink the particular table

SQL> alter table emp shrink space;

table altered

disable the row movement

SQL> alter table emp disable row movement;

table altered

Now issue the free_space sql on tablespace and check the space.

Thats it!
Thanks!