With such a broad range of software that runs against Oracle, some of it from third party vendors, I don't see Oracle making changes that would break existing applications.
But they could and have allowed for you to make it mandatory yourself. Perhaps they even make it so in their internal development.
Start with a simple procedure:
create or replace procedure do_it is
begin
dbms_output.put_line('Humbug');
end do_it;
/
If we compile it with all the warnings enabled, we get the "Missing AUTHID clause" warning.
XE> alter session set plsql_warnings='ENABLE:ALL';
XE> alter procedure do_it compile;
SP2-0805: Procedure altered with compilation warnings
XE> select text, attribute from user_errors where name = 'DO_IT';
TEXT ATTRIBUTE
-------------------------------------------------------------------------------- ---------
PLW-05018: unit DO_IT omitted optional AUTHID clause; default value DEFINER used WARNINGXE> exec do_it
Humbug
But we can use the PLSQL_WARNINGS setting to make enforcement more "Judge Dredd".
XE> alter procedure do_it compile plsql_warnings='ENABLE:ALL','ERROR:05018';
Warning: Procedure altered with compilation errors.
XE> select text, attribute from user_errors where name = 'DO_IT';
TEXT ATTRIBUTE
-------------------------------------------------------------------------------- ---------
PLS-05018: unit DO_IT omitted optional AUTHID clause; default value DEFINER used ERROR
XE> exec do_it
BEGIN do_it; END;
*
ERROR at line 1:
ORA-06550: line 1, column 7:
PLS-00905: object GARY.DO_IT is invalid
ORA-06550: line 1, column 7:
PL/SQL: Statement ignored
Rather than just enabling the warning, we can treat it as an error, effectively making the clause mandatory in our environment. Obviously it doesn't make sense for this particular warning to be set at the program unit level. It might make sense for other warnings to be set as errors at the schema or database level, and then individual overrides can be set for exceptional program units.
