notes

Common

SQL vs NoSQL

1. SQL
   • Pros
     • stores data in uniform way, so that you could query anything
     • data is consitent in the meaning of relations
     • no dublicated data => easy to update
     • consistency, regarding foreign keys
   • Cons
     • challenging to scale horizontally
     • difficult to change schema on a big running system
     • joins are very time consuming
2. NoSQL
   • Pros
     • easy to scale horizontally
     • better performance due to data locality
     • schema flexibility
   • Cons
     • there is data dublication
     • it’s very tricky, and almost impossible to implement many-to-mane relationship
     • data ara not stored in uniform way, that means that you are restricred in the variety of queires you can perform
     • some queries will be very heavy, especially “join-like”. And most of the NoSQL engines does not supports joins
3. Usually if you don’t work with huge scale it’s better to use traditional SQL database