The challenge.
A major insurance company
based in Switzerland was adopting an
Oracle-based data
warehousing and data mart solution. They lacked
the
expertise and tools to redevelop existing COBOL / DB2 code and
ETL logic to enable the seamless transition to an Oracle
environment.
Our solution.
The generated COBOL/ DB2 code
from the PRISM tool had been
modified during the lifecycle of
the legacy data warehouse. So we
decided to use the generated
COBOL / DB2 code for understanding
the ETL process rather than
the PRISM specifications.
NIIT Technologies used in-house developed code mining tools to
parse
the generated COBOL code and derive out the ETL
transformations and mapping specifications. The ETL logic was
redeveloped in an Informatica/ Oracle environment.
The DB2 data warehouses and data marts were migrated over to the
new Oracle-based database environment Regression testing was
adopted as the test strategy. The original COBOL based ETL
processing streams were run in the legacy AIX environment end to
end. The new Informatica based processing streams were run for the
same host extracts that had been fed into the legacy side. Scripts
were developed to compare the end point updating taking place in the
legacy DB2 and new Oracle databases. Acceptance testing was defined
to be successful is the end point data updating happening in the
Oracle databases was the same as that occurring in the legacy DB2
data warehouses and data marts.
The results.
The client’s processing
requirements were efficiently redesigned to
the new Oracle
architecture. Host systems were relieved of high-impact spikes in
demand which increased overall systems performance. A full
regression testing strategy was adopted which continues to help the
client identify and eliminate data inconsistency and other disabling
issues.