Last time the table structure changed

Question

What is the best way to find out as to when a table structure was last changed? (Like adding or modifying a column) ?
I queried LAST_DDL_TIME in the dba_objects view but the problem is that it stores the last time the table was truncated (using TRUNCATE TABLE table_name), as we do truncates often. I was interested in find out when the table was altered. Any ideas ?

Answer 1

Hi,
i think database trigger will do better according to your need....
its simple and best.
Just create a new table and database trigger.
Like
create table db_ddl_log
username varchar2(30),
ddl_date date,
ddl_type varchar2(30),
object_type varchar2(18),
owner varchar2(30),
object_name varchar2(128)
create or replace trigger db_DDL_Trigger
AFTER DDL ON DATABASE
BEGIN
insert into db_ddl_log
username,
ddl_date,
ddl_type,
object_type,
owner,
object_name
VALUES
ora_login_user,
sysdate,
ora_sysevent,
ora_dict_obj_type,
ora_dict_obj_owner,
ora_dict_obj_name
END;
now check it.
SQL> select * from db_ddl_log;
no rows selected
SQL> desc a
Name Null? Type
NO NUMBER
SQL> alter table a add (name varchar2(1));
Table altered.
1* select * from db_ddl_log
USERNAME DDL_DATE DDL_TYPE OBJECT_TYPE OWNER OBJECT_NAME
SYS 06-MAR-06 ALTER TABLE SYS A
SQL> truncate table a;
Table truncated.
sql> select * from db_ddl_log
USERNAME DDL_DATE DDL_TYPE OBJECT_TYPE OWNER OBJECT_NAME
SYS 06-MAR-06 ALTER TABLE SYS A
SYS 06-MAR-06 TRUNCATE TABLE SYS A
Thanks
Kuljeet Pal Singh