You can read whatever you want out of the data dictionary. It is not possible to read the CREATE statment out from anywhere. The DROP we do not need to read (you can reconstruct that). The alter we can get (but don't forget -- some alters are CREATES in disguise!!! alter table t add constraint, that is really a CREATE constraint)..

For example:

tkyte@TKYTE816> create table log
2 ( operation varchar2(25),
3 owner varchar2(25),
4 name varchar2(25),
5 extra varchar2(4000) );

Table created.

tkyte@TKYTE816>
tkyte@TKYTE816> create or replace trigger ddl_trigger
2 after create or alter or drop on SCHEMA
3 declare
4 l_sysevent varchar2(25);
5 l_extra varchar2(4000);
6 begin
7 select ora_sysevent into l_sysevent from dual;
8
9 if ( l_sysevent in ('DROP','CREATE') )
10 then
11 if l_sysevent = 'CREATE'
12 then
13 begin
14 select 'storage ( initial ' || initial_extent ||
15 ' next ' || next_extent || ' .... )'
into l_extra
16 from all_tables
where table_name = ora_dict_obj_name
17 and owner = user;
18 exception
19 when no_data_found then null;
20 end;
21 end if;
22
23 insert into log
24 select ora_sysevent, ora_dict_obj_owner,
25 ora_dict_obj_name, l_extra
26 from dual;
27 elsif ( l_sysevent = 'ALTER' )
28 then
29 insert into log
30 select ora_sysevent, ora_dict_obj_owner,
31 ora_dict_obj_name, sql_text
32 from v$open_cursor
33 where upper(sql_text) like 'ALTER%' ||
34 ora_dict_obj_name || '%'
35 and sid = ( select sid
36 from v$session
37 where audsid=userenv('sessionid') );
38 end if;
39 end;
40 /

Trigger created.

tkyte@TKYTE816> drop table t;
Table dropped.

tkyte@TKYTE816> create table t ( x int );
Table created.

tkyte@TKYTE816> alter table t add y date;
Table altered.

tkyte@TKYTE816> select * from log;

OPERATION OWNER NAME EXTRA
--------- ----- ---- -------------------------------------------
DROP TKYTE T
CREATE TKYTE T storage ( initial 131072 next 131072 .... )
ALTER TKYTE T alter table t add y date