What is the difference between a "procedure name IS' and a "Procedure name AS" in Oracle?

Question

PROCEDURE sample (p_num1 IN TABLE%TYPE, p_num2 OUT NUMBER) IS

OR

PROCEDURE sample (p_num1 IN TABLE%TYPE, p_num2 OUT NUMBER) AS

Answer 1

The difference is only one letter: I vs. A. You can use both, there won't be any other difference. The effect of executing both is the same except for the same minor difference stored in the data dictionary tables [CDB|DBA|ALL|USER]_SOURCE.

SQL> create or replace procedure p_test is begin null; end;
  2  /

Procedure created.

    SQL> create or replace procedure p_test as begin null; end;
      2  /

    Procedure created.

    SQL>

Note that it doesn't work for e.g. views:

SQL> create or replace view v_emp as select * from emp;

View created.

SQL> create or replace view v_emp is select * from emp;
create or replace view v_emp is select * from emp
                             *
ERROR at line 1:
ORA-00905: missing keyword