Introducing Delta Lake

Using a data lake has become the de facto solution for many data engineering tasks. This storage layer is composed of files that can be arranged in a historical way instead of tables in a data warehouse. This has the benefit of decoupling storage from computing, which is the great advantage of data lakes. They are much cheaper than a database. The data that's stored in the data lake has no primary and foreign keys, making it hard to extract the information stored on it. Therefore, data lakes are seen as a solution where we only append new data. When trying to query or delete records, we need to go through all the files in the data lake, which could be a very resource-intensive and slow task.

This leads to data lakes being hard to update, and they may have problems when we try to use them in cases where data needs to be frequently queried. This includes customer or transactional data, financial applications that require robust data handling, or when we...