<font color=#660033>SQL> SET SERVEROUTPUT ON
SQL> CREATE OR REPLACE PACKAGE pkg
  2  AS
  3      g_global_value       VARCHAR2(1);
  4      PROCEDURE p (p_param IN VARCHAR2);
  5  END pkg;
  6  /
 
Package created.
 
SQL> CREATE OR REPLACE PACKAGE BODY pkg
  2  AS
  3      PROCEDURE p (p_param IN VARCHAR2)
  4      IS
  5      BEGIN
  6          g_global_value := SUBSTR(p_param,1,1);
  7      END p;
  8  END pkg;
  9  /
 
Package body created.
 
SQL> EXEC pkg.p('A');
 
PL/SQL procedure successfully completed.
 
SQL></font>

<font color=#0000cc>SQL> SET SERVEROUTPUT ON
SQL> EXEC pkg.p('B');
 
PL/SQL procedure successfully completed.
 
SQL></font>

<font color=#660033>SQL> EXEC DBMS_OUTPUT.PUT_LINE(pkg.g_global_value);</font>

<font color=#660033>SQL> EXEC DBMS_OUTPUT.PUT_LINE(pkg.g_global_value);
A
 
PL/SQL procedure successfully completed.
 
SQL></font>