Data Lake v/s Data Warehouse v/s Operational Databases

In the past few days, several people have asked me to explain the difference between Data Lakes and Data Warehouses (and the use cases for these, especially when you can build analytics around Transactional Databases directly). So, I decided to write a blog post to capture the concepts and use cases around these.

While all have a storage aspect to it, but to keep the post simple, we will assume that each of these is a database, albeit the underlying database technologies usually differ.