SQL vs NoSQL

Factors to consider when selecting SQL or NoSQL database

•     Data Structure

If the data is structured, then the best choice would be the SQL database.

The SQL database fits well for transaction-oriented systems such as customer relationship management tools, accounting software and e-commerce platforms. Each row is an entity while each row is an attribute which describes that entity (Eg:- Entity = Customer , Attributes = name , address , job , etc.)

As an example; Banking system is a highly transactional system. Durability is very high. It means once a transaction has been committed to the database, it is considered as permanent, even if there is a system failure. In that kind of a situation the best database would be SQL database.

 

On the other hand, if the data requirements are not clear or the data is unstructured, then the best choice would be the NoSQL database.

When storing data in NoSQL database, it does not need a predefined schema like SQL database. Data in a NoSQL database can be column stores, document oriented, graph-based or key-value pairs. That special quality provides much more flexibility.

•     Ability to Query data

In this factor, we need to consider how quickly we need to run queries and who will be responsible for running those queries.

If the data is nicely structured and organized, it is better to query the data with SQL database. Because it efficiently executes queries and retrieves and edits data.

It is light-weight and easy to learn. Queries can be run with a less number of technical staff. ( people like, business analysts and marketers are belong to the technical staff category )

When developing NoSQL queries, developers focused scalability and flexibility not on query efficiency. So when running NoSQL queries, user must perform some extra processes.

•     Scaling

SQL and NoSQL scales differently.

SQL databases scale vertically. It means capacity of a single server can be increased to increase the scalability of the SQL database ( CPU , RAM or SSD could be increased ).  SQL databases were designed to run on a single server to maintain the integrity of the data. So that scaling the SQL database is not easy.

On the other hand NoSQL database scale horizontally. It means more servers can be added in-order to increase the scalability of a NoSQL database. This is a huge advantage that NoSQL has over  SQL. So that scaling NoSQL database is not that much difficult.