Moving and transforming data using ETL
A data pipeline is an artifact of a data engineering process. It transforms raw data into data ready for analytics. These in turn help solve problems, aid support decisions, and make our lives more convenient. In some ways, it can be thought of as the stitch between the OLTP and OLAP systems. Data pipelines are sometimes referred to as ETL, which stands for extract, transform, load, and it has a variation called extract, load, transform (ELT). The main difference between the two is whether the incoming data is first saved to disk and then transformed (data wrangling) or vice versa. The processing is loosely referred to as ETL. Although, it is fair to say ELT is relevant in the context of Data Lakes and unstructured data, whereas ETL is used for Data Warehouses. The following diagram shows how ETL bridges the gap between the OLTP and OLAP systems:
Figure 2.9 – ETL stitches OLTP and OLAP systems
Data pipelines include...
