SQL> select count(*) from dba_objects where status='INVALID';

  COUNT(*)
----------
       181

SQL> exec dbms_utility.compile_schema('SYS');
BEGIN dbms_utility.compile_schema('SYS'); END;

*
ERROR at line 1:
ORA-20001: Cannot recompile SYS objects
ORA-06512: at "SYS.DBMS_UTILITY", line 387
ORA-06512: at line 1

SQL> @?/rdbms/admin/utlrp

TIMESTAMP
--------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
COMP_TIMESTAMP UTLRP_BGN  2020-12-18 14:24:13

DOC>   The following PL/SQL block invokes UTL_RECOMP to recompile invalid
DOC>   objects in the database. Recompilation time is proportional to the
DOC>   number of invalid objects in the database, so this command may take
DOC>   a long time to execute on a database with a large number of invalid
DOC>   objects.
DOC>
DOC>   Use the following queries to track recompilation progress:
DOC>
DOC>   1. Query returning the number of invalid objects remaining. This
DOC>      number should decrease with time.
DOC>         SELECT COUNT(*) FROM obj$ WHERE status IN (4, 5, 6);
DOC>
DOC>   2. Query returning the number of objects compiled so far. This number
DOC>      should increase with time.
DOC>         SELECT COUNT(*) FROM UTL_RECOMP_COMPILED;
DOC>
DOC>   This script automatically chooses serial or parallel recompilation
DOC>   based on the number of CPUs available (parameter cpu_count) multiplied
DOC>   by the number of threads per CPU (parameter parallel_threads_per_cpu).
DOC>   On RAC, this number is added across all RAC nodes.
DOC>
DOC>   UTL_RECOMP uses DBMS_SCHEDULER to create jobs for parallel
DOC>   recompilation. Jobs are created without instance affinity so that they
DOC>   can migrate across RAC nodes. Use the following queries to verify
DOC>   whether UTL_RECOMP jobs are being created and run correctly:
DOC>
DOC>   1. Query showing jobs created by UTL_RECOMP
DOC>         SELECT job_name FROM dba_scheduler_jobs
DOC>            WHERE job_name like 'UTL_RECOMP_SLAVE_%';
DOC>
DOC>   2. Query showing UTL_RECOMP jobs that are running
DOC>         SELECT job_name FROM dba_scheduler_running_jobs
DOC>            WHERE job_name like 'UTL_RECOMP_SLAVE_%';
DOC>#

PL/SQL procedure successfully completed.


TIMESTAMP
--------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
COMP_TIMESTAMP UTLRP_END  2020-12-18 14:24:32

DOC> The following query reports the number of objects that have compiled
DOC> with errors.
DOC>
DOC> If the number is higher than expected, please examine the error
DOC> messages reported with each object (using SHOW ERRORS) to see if they
DOC> point to system misconfiguration or resource constraints that must be
DOC> fixed before attempting to recompile these objects.
DOC>#

OBJECTS WITH ERRORS
-------------------
                  0

DOC> The following query reports the number of errors caught during
DOC> recompilation. If this number is non-zero, please query the error
DOC> messages in the table UTL_RECOMP_ERRORS to see if any of these errors
DOC> are due to misconfiguration or resource constraints that must be
DOC> fixed before objects can compile successfully.
DOC>#

ERRORS DURING RECOMPILATION
---------------------------
                          0


Function created.


PL/SQL procedure successfully completed.


Function dropped.

...(14:24:56) Starting validate_apex for APEX_190200
...(14:24:57) Checking missing sys privileges
...(14:24:57) Re-generating APEX_190200.wwv_flow_db_version
... wwv_flow_db_version is up to date
...(14:24:57) Key object existence check
...(14:24:58) Setting DBMS Registry for APEX to valid
...(14:24:58) Exiting validate_apex

PL/SQL procedure successfully completed.