1. Log in as the oracle user.  Confirm that your ORACLE_HOME
   and PATH environment variables refer to the 11g software
   home.

2. Change to the 11g ORACLE_HOME directory:

     cd $ORACLE_HOME/rdbms/admin

3. Log in to 'sqlplus' and invoke the script utlrp.sql:

     sqlplus / as sysdba @utlrp.sql

4. The script will re-compile all the necessary PL/SQL
   programs in the database using the 11g PL/SQL compiler.

5. In SQL*Plus, check for invalid objects.

     SELECT COUNT(*) FROM dba_invalid_objects;

