How to implement "delete" on a table using OWB?

Question

Hi All,
How do I implement a simple delete using OWB?
Assumption:
(1) Table abcd (id number, age number, amt number)
(2) the_number is a variable
(3) the_id is a variable
Want to implement following transformation in OWB?
DELETE FROM ABCD WHERE AMT=0 AND number = the_number AND id = the_id ;
Rgds,
Deepak

Answer 1

We implemented delete mappings, and delete flows to be able to reverse a failed load. This is in my opinion a very sound and valid reason for deleting from a datawarehouse. Also if the need is there it could be used for deleting old superfluous data from the datawarehouse.
There are a few things to consider: closed records in type II should be opened up (post mapping).
Test, test, test.
It is indeed a bit tricky to realize,but certainly working and possible.
steps to take are following:
1) create new mapping
2) drop mapping table where to delete from onto mapping (2 times, 1 source, 1 target)
3) map all fields from source to their corresponding fields in target, except the ones that determine the "where" clause (Refered to as filter fields)
4) Either create a select, or a mapping input parameter which should result in generating the filter-values for your delete.
5) map above step to the filter fields.
6)define a delete mapping by altering target table properties as follows:
6a) Loading Type => Delete
6b) Match by constraint => No constraints
7) set properties each field as folows:
7a) filter fields match column when deleting => Yes
7b) other fields match column when deleting => No
Hope this helps,
Wilco