SQL & PL/SQL

Hi All,

I have one unique index on the empno column and the table name is EMP, so emp table doesn't allowing me to insert duplicate values into empno column then I have tried to disable an index by using the following statement

alter index <index_name> unusable;
The index got altered.

But the problem is when I am trying to insert duplicate values into empno column
oracle showing the following error message.

ERROR at line 1:
ORA-01502: index 'Index Name' or partition of such index is in unusable
state

I am using oracle 10g.

Please any one help me...

Thanks in advance!