Posted by I saw this on an ideas forum today
and whilst most people would take care of this with a source code control system, its also true that people might do several compilations / tests with their PLSQL source before checking it in officially to their source repository.
So the idea has some merit… and maybe we can roll our own without too much fuss. I make no claims that this is a ‘complete’ solution, but it should get you going 
SQL> set timing off
SQL> drop trigger plsql_trigger;
Trigger dropped.
SQL>
SQL> drop table plsql_params purge;
Table dropped.
SQL> drop table plsql_history cascade constraints purge;
Table dropped.
SQL> drop table plsql_history_source cascade constraints purge;
Table dropped.
SQL> drop table plsql_log cascade constraints purge;
Table dropped.
SQL>
SQL>
SQL> create table plsql_params
2 as select 3 versions_kept from dual;
Table created.
SQL>
SQL> create table plsql_history (
2 TSTAMP TIMESTAMP
3 ,OWNER VARCHAR2(128)
4 ,NAME VARCHAR2(128)
5 ,TYPE VARCHAR2(12)
6 ,constraint plsql_history_pk primary key ( tstamp,owner,name,type)
7 )
8 organization index;
Table created.
SQL>
SQL> create table plsql_history_source (
2 TSTAMP TIMESTAMP
3 ,OWNER VARCHAR2(128)
4 ,NAME VARCHAR2(128)
5 ,TYPE VARCHAR2(12)
6 ,LINE NUMBER
7 ,TEXT VARCHAR2(4000)
8 ,constraint plsql_history_source_pk primary key ( tstamp,owner,name,type,line)
9 ,constraint plsql_history_source_fk foreign key ( tstamp,owner,name,type) references plsql_history ( tstamp,owner,name,type )
10 );
Table created.
SQL>
SQL> create table plsql_log
2 (
3 TSTAMP TIMESTAMP
4 ,MSG varchar2(1000)
5 );
Table created.
SQL>
SQL>
SQL> create or replace trigger plsql_trigger
2 before create on SCHEMA
3 declare
4 l_owner varchar2(128) := ora_dict_obj_owner;
5 l_name varchar2(128) := ora_dict_obj_name;
6 l_type varchar2(128) := ora_dict_obj_type;
7 l_archived timestamp := systimestamp;
8 l_tstamp_to_clear timestamp;
9
10 procedure logger(m varchar2) is
11 pragma autonomous_transaction;
12 begin
13 insert into plsql_log values (systimestamp,m);
14 commit;
15 end;
16 begin
17 if l_type in ('FUNCTION','PROCEDURE','PACKAGE','PACKAGE BODY') then
18 insert into plsql_history values (l_archived, l_owner, l_name, l_type);
19
20 insert into plsql_history_source
21 select l_archived, owner, name, type, line, text
22 from dba_source
23 where owner = l_owner
24 and name = l_name
25 and type = l_type;
26
27 logger('Archived '||l_type||'-'||l_owner||'.'||l_name);
28
29 select max(case when tot > versions_kept and seq = tot - versions_kept then tstamp end)
30 into l_tstamp_to_clear
31 from plsql_params,
32 ( select ph.*,
33 row_number() over ( order by tstamp ) as seq,
34 count(*) over () as tot
35 from plsql_history ph
36 )
37 where owner = l_owner
38 and name = l_name
39 and type = l_type;
40
41 if l_tstamp_to_clear is not null then
42 logger('Clearance timestamp for '||l_type||'-'||l_owner||'.'||l_name||' is '||l_tstamp_to_clear);
43
44 delete from plsql_history_source where tstamp <= l_tstamp_to_clear;
45 delete from plsql_history where tstamp <= l_tstamp_to_clear; 46 logger('Cleared '||sql%rowcount||' versions for '||l_type||'-'||l_owner||'.'||l_name); 47 end if; 48 end if; 49 end; 50 / Trigger created. SQL>
SQL> create or replace procedure P_TEST is
2 begin
3 null; -- version 1
4 end;
5 /
Procedure created.
SQL>
SQL> create or replace procedure P_TEST is
2 begin
3 null; -- version 2
4 end;
5 /
Procedure created.
SQL>
SQL>
SQL> create or replace procedure P_TEST is
2 begin
3 null; -- version 3
4 end;
5 /
Procedure created.
SQL>
SQL>
SQL> create or replace procedure P_TEST is
2 begin
3 null; -- version 4
4 end;
5 /
Procedure created.
SQL>
SQL>
SQL> create or replace procedure P_TEST is
2 begin
3 null; -- version 5
4 end;
5 /
Procedure created.
SQL> select * from plsql_history;
TSTAMP OWNER NAME TYPE
---------------------------------- ------------ ------------ ---------------
02-FEB-16 12.12.42.280000 PM MCDONAC P_TEST PROCEDURE
02-FEB-16 12.12.42.306000 PM MCDONAC P_TEST PROCEDURE
02-FEB-16 12.12.42.339000 PM MCDONAC P_TEST PROCEDURE
SQL>
SQL> select tstamp, text from plsql_history_source;
TSTAMP TEXT
---------------------------------- ------------------------------------------------------------
02-FEB-16 12.12.42.280000 PM procedure P_TEST is
02-FEB-16 12.12.42.280000 PM begin
02-FEB-16 12.12.42.280000 PM null; -- version 2
02-FEB-16 12.12.42.280000 PM end;
02-FEB-16 12.12.42.306000 PM procedure P_TEST is
02-FEB-16 12.12.42.306000 PM begin
02-FEB-16 12.12.42.306000 PM null; -- version 3
02-FEB-16 12.12.42.306000 PM end;
02-FEB-16 12.12.42.339000 PM procedure P_TEST is
02-FEB-16 12.12.42.339000 PM begin
02-FEB-16 12.12.42.339000 PM null; -- version 4
02-FEB-16 12.12.42.339000 PM end;
12 rows selected.
SQL>
SQL> select * from plsql_log;
TSTAMP MSG
---------------------------------- --------------------------------------------------------------------------------
02-FEB-16 12.12.42.221000 PM Archived PROCEDURE-MCDONAC.P_TEST
02-FEB-16 12.12.42.255000 PM Archived PROCEDURE-MCDONAC.P_TEST
02-FEB-16 12.12.42.281000 PM Archived PROCEDURE-MCDONAC.P_TEST
02-FEB-16 12.12.42.307000 PM Archived PROCEDURE-MCDONAC.P_TEST
02-FEB-16 12.12.42.307000 PM Clearance timestamp for PROCEDURE-MCDONAC.P_TEST is 02-FEB-16 12.12.42.181000 PM
02-FEB-16 12.12.42.313000 PM Cleared 1 versions for PROCEDURE-MCDONAC.P_TEST
02-FEB-16 12.12.42.340000 PM Archived PROCEDURE-MCDONAC.P_TEST
02-FEB-16 12.12.42.340000 PM Clearance timestamp for PROCEDURE-MCDONAC.P_TEST is 02-FEB-16 12.12.42.254000 PM
02-FEB-16 12.12.42.340000 PM Cleared 1 versions for PROCEDURE-MCDONAC.P_TEST
9 rows selected.
Learning is not a spectator sport 
Very usefull
We did something similar using a DDL trigger which logged the user, the time, the object name and the ddl into a table (ddl stored in a clob). Very useful when developers lose changes or when we are trying to find out who created or modified an object.
Reblogged this on Oracle, Web, Script, SQLserver, Tips & Trick and commented:
Auto backups of plsql source