Designing principle of auditing the DML on a specific table?

Question

Hi All,
What is the designing principle of auditing the DML performed on a table? or a bunch of tables?
I know Oracle provides the auditing capability and there is Fine-Grained auditing available to use to keep track of row/column level changes.
However, in this case, since we want to keep all the changing history of the table, and we want to do it our own way, we don`t want to use the Oracle`s FGA.
the scenario is:
I have a table with 40 columns, and any one of them might be updated, including the primary key. (it sucks and bad)
we want to keep track of all the changes performed on this table, mainly DML.
the table structure I came up with is as below and it doesn`t look good or feel right.
So, could you share some experiences of how your design the table in this scenario? and the basic principle or rule to follow?
CREATE TABLE TBS (COL1 VARCHAR2(10), COL2 VARCHAR2(20), COL3 VARCHAR2(20), COL4 VARCHAR2(30)....., COL40 VARCHAR2(50));
CREATE TABLE tbs_audit (
SEQ_NUM NUMBER,
USER_NAME VARCHAR2(50),
UPD_DT TIMESTAMP,
OPERATION_TYPE VARCHAR2(20),
COL1_OLD_VAL VARCHAR2(10),
COL2_OLD_VAL VARCHAR2(20),
COL40_OLD_VAL VARCHAR2(50));Thanks in advance!

Answer 1

I would definitely put the auditing records into another table.
What I am struggling with is:
whether should I record the changed columns only or the whole row? to me, the first one is better. it saves space, and it comes easy when I want to display the changed history of certain columns.
And for the first one, should I use table structure like 1) or 2)? which one is better? why?
1)
CREATE TABLE tbs_audit (
SEQ_NUM NUMBER,
USER_NAME VARCHAR2(50),
UPD_DT TIMESTAMP,
OPERATION_TYPE VARCHAR2(20),
COL1_OLD_VAL VARCHAR2(10),
COL2_OLD_VAL VARCHAR2(20),
COL40_OLD_VAL VARCHAR2(50));
2)
CREATE TABLE tbs_audit (
SEQ_NUM NUMBER,
USER_NAME VARCHAR2(50),
UPD_DT TIMESTAMP,
OPERATION_TYPE VARCHAR2(20),
COL_name VARCHAR2(10),
COL_OLD_VAL VARCHAR2(20)
);