relational vs non-relational databases

1. https://www.pluralsight.com/blog/software-development/relational-non-relational-databases
2. Use cases for NoSQL databases
   
   1 To store documents
   2 Flexible schema and flexible data type
   3 Fast Key Value Access and massive write performance
   4 Distributed System Support and Schema migration
   
   Use cases for relational databases
   1 To implement transactions
   2 To apply referential integrity 
   3 To use mature ORM framework like hibernate to map objects to the rows of a table