What is a relational DBMS? (Database Management System) The modeling of relationships between values.
This is good because it makes sure everything is consistent.
Thus it is a repository that sits on the management system. The integrity of the RDBMS is a huge advantage.
Here are a couple of advantages and disadvantage: Advantages - for simple data types - query - better backup procedures Disadvantages - difficult to distribute and partition - difficult to represent hierarchies
ACID vs BASE ACID - RDBMS BASE - all about availability and performance
NOSQL - changes the way it models the data in the sense that it doesn't view everything as a relations - performance is usually better - usually stored based on columns or key/value pair
CAP Theorem Consistency - single up-to-date copy of the data Availability - every request reviewed must come with a response Partition Tolerence - allowed to lose arbitrary messages. The theorem states that you can only possess two of these traits at any given time.
*Remember this is not good for hard time real time DBS. Only for situations where returning the wrong data doesn't do any damage.