What are the trade-offs between scalability and consistency in databases?

What are the trade-offs between scalability and consistency in databases?

In databases, scalability refers to the ability to handle increased load, while consistency ensures that all users see the same data at the same time. The trade-off often involves choosing between a system that can scale easily but may sacrifice consistency, or one that maintains strong consistency but struggles to scale.

Can you give an example of a system that prioritizes scalability over consistency?

Sure! A common example is a NoSQL database like Cassandra. It allows for high scalability and availability, but it uses eventual consistency, meaning that not all nodes may have the latest data at the same time.

What about a system that prioritizes consistency?

An example of a system that prioritizes consistency is a traditional relational database like PostgreSQL. It ensures strong consistency through ACID transactions, but it may not scale as easily as NoSQL solutions under heavy load.

How do developers decide which to prioritize?

Developers typically assess their application's requirements. If real-time data accuracy is crucial, they may prioritize consistency. If they expect high traffic and need to handle large volumes of data, scalability might take precedence.