Creating a History via Mapping

Question

Hi,
i´m not yet really experienced with Owb-Mappings and came accross a problem when trying to create a History of a Table.
Out of some reason i get inconsistent results.
In my Tables i´m using following structure:
ID (Primary_key) Key Datacolumbs valid_from valid_to aktive
123 01.01.2009 123 abcd 01.01.2009 01.01.2222 1
So when something in this Row changes, the old one should be updated and a new one created.
ID (Primary_key) Key Datacolumbs valid_from valid_to aktive
123 01.01.2009 123 abcd 01.01.2009 12.05.2009 0
123 13.05.2009 123 abcdefg 13.05.2009 01.01.2222 1
The ID is generated out of the Key and the valid_from timestamp.
In the Mapping im creating the new Datarows and am doing a MINUS with NEW_DATA i created via ETL and the the OLD_DATA from the Table im going to update.
The result should be the Datarows that are new or have changed.
Then im doing a JOIN of the NEW_DATA and the OLD_DATA over "new_data.key = old_data.key AND old_data.aktive = 1".
This way i should get the old version of the Datarows that have changed.
Then i give those 2 Results each a set of parameters, for the new/changed ones: valid_from = sysdate, valid_to = '01.01.2222', aktive = 1
and for the old outdated ones: valid_to = (sysdate-1), aktive = 0
This way parameterized i send dem into an UNION-Operator.
After the Union i have an Expression to create the ID (a simple concatenate of the the key and valid_from)
The result of that all should look like shown above, but instead i sometimes get
ID (Primary_key) Key Datacolumbs valid_from valid_to aktive
123 01.01.2009 123 abcd 01.01.2009 01.01.2222 1
123 13.05.2009 123 abcdefg 13.05.2009 01.01.2222 1
OR
ID (Primary_key) Key Datacolumbs valid_from valid_to aktive
123 01.01.2009 123 abcd 01.01.2009 12.05.2009 1
123 13.05.2009 123 abcdefg 13.05.2009 01.01.2222 1
if i use Update/insert (Match via PK).
Can you help me please where there is the error, i don´t get it.
It would be great if there was a "pest practise" how to do that.
Greetings from Germany
Martin

Answer 1

How can one post the screenshort of the maping on the forum? plz advice.Upload your image to any image hosting site (or your own website if you have it),
during forum message creation enclose full URL to your picture in exclamation mark (on message creation page on the right side you can find more tags for formating of message).
Martin, look at my variant of history mapping designed according Oracle SCD best practice:
!http://www.geocities.com/tsibulnyak/owb_scd2map.jpg!
Regards,
Oleg