Oracle: How to check the NLS_CHARCTERSET of the database?

The following query will do it:

SELECT value$ FROM sys.props$ WHERE name = 'NLS_CHARACTERSET' ;

How to debug "Warning: View created with compilation errors." ?

SQL>alter view MY_VIEW compile;

Warning: View created with compilation errors.

So how do we know what the errors is?

One way is shown below:

SQL> show errors view MY_VIEW

Errors for VIEW MY_VIEW:

LINE/COL ERROR

-------- -----------------------------------------------------------------

0/0      ORA-01031: insufficient privileges