SQL vs NoSQL is the Wrong Distinction
A misconception that I held for a really long time was that systems that use SQL (Structured Query Language) are by definition relational databases, and systems that don’t (e.g., MongoDB, Cassandra) are non-relational. It’s easy to understand whether a database uses SQL or not, but what does it mean when we say a database is relational? At a minimum, relational databases expose data in the form of “relations,” another word for tables with rows and columns.
Google App Engine Data Store No Structured Query Language Relational Databases Google App Engine Data Store Data Lake
Source: softwareatscale.dev