Introduction

Since ODI is frequently used during data warehouse load operations, it is only natural that the functional requirements of Slowly Changing Dimensions (SCD) and Changed Data Capture (CDC) be addressed as part of its core functionality. By encapsulating the complexities of these two methodologies within the delivered set of KMs, ODI allows the developer to focus on answering the questions of what, when, and where, while leaving the seemingly complex issue of how to be managed by the KMs.

Although unrelated to each other, SCD and CDC KMs are both integral parts of many ETL/ELT solutions. Unfortunately, the techniques these processes employ are not often well known or understood. So in order to understand how these advanced topics may be addressed by ODI, we begin by defining these terms:

• SCD is a name for a process that loads data into dimension tables, where the data changes slowly rather than changing on a time-based or regular schedule. The dimension tables are structured in a...