In Oracle 10g
SQL> ALTER SESSION SET PLSQL_CODE_TYPE='NATIVE';

Session altered.

SQL> ALTER PROCEDURE test_speed COMPILE;

Warning: Procedure altered with compilation errors.

SQL> show errors
Errors for PROCEDURE TEST_SPEED:

LINE/COL ERROR
-------- -----------------------------------------------------------------
0/0 PLS-00923: native compilation failed: Visual Studio not
found::Could not open registry key
HKEY_LOCAL_MACHINE\SOFTWARE\MICROSOFT\VISUALSTUDIO\7.0\SETUP:No
error

what i have to do to test plsql_code_type='NATIVE' ?