James Serra defines the term “data lakehouse”:
As a follow-up to my blog Data Lakehouse & Synapse, I wanted to talk about the various definitions I am seeing about what a data lakehouse is, including a recent paper by Databricks.
Databricks uses the term “Lakehouse” in their paper (see Lakehouse: A New Generation of Open Platforms that Unify Data Warehousing and Advanced Analytics), which argues that the data warehouse architecture as we know it today will wither in the coming years and be replaced by a new architectural pattern, the Lakehouse. Instead of the two-tier data lake + relational data warehouse model, you will just need a data lake, which is made possible by implementing data warehousing functionality over open data lake file formats.
While I agree there may be some uses cases where technical designs may allow Lakehouse systems to completely replace relational data warehouses, I believe those use cases are much more limited than this paper suggests.
James is a sharp and perceptive fellow, so read the whole thing.