dellera@ORACLE9I> 
dellera@ORACLE9I> create table t1 (x int);

Table created.

dellera@ORACLE9I> create table t2 (x int);

Table created.

dellera@ORACLE9I> 
dellera@ORACLE9I> create or replace package as_of_scn_views_pkg is
  2  
  3  -- get the current SCN
  4  function get_remote_scn return number;
  5  
  6  -- create an as-of-scn view reading at the point in time
  7  -- defined by the parameter p_as_of_scn
  8  procedure create_as_of_scn_view (
  9    p_table_name varchar2,
 10    p_view_name  varchar2,
 11    p_as_of_scn  number
 12  );
 13  
 14  end as_of_scn_views_pkg;
 15  /

Package created.

dellera@ORACLE9I> show errors;
No errors.
dellera@ORACLE9I> 
dellera@ORACLE9I> create or replace package body as_of_scn_views_pkg is
  2  
  3  function get_remote_scn return number is
  4  begin
  5    return sys.dbms_flashback.get_system_change_number;
  6  end get_remote_scn;
  7  
  8  procedure create_as_of_scn_view (
  9    p_table_name varchar2,
 10    p_view_name  varchar2,
 11    p_as_of_scn  number)
 12  is
 13    l_stmt long;
 14  begin
 15    l_stmt := 'create or replace view ' || p_view_name ||
 16  		  ' as select * from ' || p_table_name || ' as of scn ' || p_as_of_scn;
 17    dbms_output.put_line ('executing: '||l_stmt);
 18    execute immediate l_stmt;
 19  exception
 20    when others then
 21  	 raise_application_error (-20001, sqlerrm||' while creating '|| p_view_name);
 22  end create_as_of_scn_view;
 23  
 24  end as_of_scn_views_pkg;
 25  /

Package body created.

dellera@ORACLE9I> show errors;
No errors.
dellera@ORACLE9I> 
dellera@ORACLE9I> spool off