When a code change is required, the main consideration is how to reduce the impact of the new implementation on the existing code, thus reducing the possibility of introducing new bugs and instead keeping or improving components' high cohesion/low coupling relationship. That's when design patterns come to the rescue, offering proven solutions for almost all recurrent development needs.

When the concept of EDI (electronic data interchange) was first introduced in the 1960s, the stage was set for commerce to develop into the online shopping reality we have today. Now, e-commerce is so embedded in our society that we cannot imagine living without it.

Today, we'll discuss the ways in which ETL tools can connect, consolidate, and sync data between OLTP and OLAP systems. We'll begin by defining the uses of OLTP and OLAP systems and then explore how ETL tools can connect them.