Track and capture the changes in OWB

Question

I'm trying to merge data from two systems that have not been kept in sync. For example, I have 4 columns: my_key, lines, mod_date, and source. For the same my_key, lines changes over time (mod_date). I only want to capture the first change to lines (for a given change) regardless of which system the data comes from. Basically, I want to ignore all the rows in which my_key and lines are the same as the last row I selected. Here is some data and the desired results:
DATA in TEST_RANK table
my_key lines mod_date source rec#
A 150 01/01/2005 A 1
A 150 01/02/2005 B 2
A 100 01/14/2005 A 3
A 100 01/15/2005 B 4
A 200 01/19/2005 B 5
A 150 01/22/2005 A 6
A 150 01/25/2005 B 7
DESIRED RESULTS -
A 150 01/01/2005 A 1
A 100 01/14/2005 A 3
A 200 01/19/2005 B 5
A 150 01/22/2005 A 7
I tried w/ Ranking function but it didnt work as it looks for distinct group
SELECT * FROM ( SELECT my_key,lines,mod_date,ROW_NUMBER() OVER ( PARTITION BY my_key,lines ORDER BY mod_date ) m_rank from table_name ) where m_rank <= 1
M LINES MOD_DATE M_RANK
A 100 14-JAN-05 1
A 150 01-JAN-05 1
A 200 19-JAN-05 1
Is there any way I can do this in OWB using analytical functions ?
Thanks,
Shreedhar

Answer 1

Hi,
I don't think owb10g support analytic aggregation directly. But I know a way to introduce analytic funcations to the aggregation transformation. To achieve this, u'll have to execute some sql. Here's the sample scripts.
SELECT parameter_id,transformation_expression,parameter_name,
map_component_name,map_name,parameter_group_name
FROM all_iv_xform_map_parameters
WHERE map_name = 'MAP_DEMO'--The map name
AND MAP_COMPONENT_NAME = 'AGG_DEMO' --The aggregation name
AND PARAMETER_GROUP_NAME = 'OUTGRP1' --The group name
AND PARAMETER_NAME = 'ATTR'; --The attribute name
SELECT * FROM owb10g.cmpmappingparameter_v
WHERE elementid = &parameter_id;
UPDATE cmpallclasses
SET S3_5 = 'MAX('||chr(38)||'5)KEEP
(DENSE_RANK LAST ORDER BY '||chr(38)||'3)'
WHERE i_1 = &parameter_id;
--Here chr(38) is '&', use &5 to pass the 6th attribute
--in the input group to the analytic function
Hope this help.