How to pick your database

#systems #systemdesign #webdev #aws

One of the most asked question for system design is - "Which storage mechanism/database you will pick for the problem?"

If you are going to answer that I know X database. Hence, I would like to go with X, it would be a WRONG answer.

Neither you should be talking in terms of any database brand/name. Infact the correct way is to talk about the type of the database. Eg: Relational, document, graph etc.

Now, the question comes how one can pick the database. So, here is a short summary which can help you to take decision:

Schema	Schemaless or strict Schema
Type	What type of problem are we solving and what type of database is it?
Transaction	Is transaction integrity required or not?
Performance	How is the performance of the DB for Read and Write operations
Scalability	Is the database scalable and what would be the cost of it? Eg: Mongo, MySQL or Postgres supports scalability by DB partitioning and sharding
Opensource	Is the database open-source vendor locked? MySQL is OS, and Aurora, or DynamoDB are vendor locked (AWS)
USP	What is the unique feature of the database? Eg: Document-based DBs are easier to scale due to sharding, and Aurora is highly performant.
How you talk to DB	Which programming language a database is using. Eg: Relation MySQL uses SQL.