What are the differences between vertical and horizontal database scaling?

Vertical and horizontal scaling of databases differ in their approach to increasing performance and data processing volume:

• Vertical scaling (scale-up):

  • Increasing resources of a single server — adding CPU, memory, disk space.
  • Easier to implement, does not require changes in application architecture.
  • Limited by the maximum capabilities of the hardware.
  • Example: replacing the server with a more powerful one.

• Horizontal scaling (scale-out):

  • Adding new servers (nodes) to the database cluster.
  • Requires data and load distribution among servers (sharding, replication).
  • Allows handling more requests and storing more data.
  • More complex in setup and maintenance.

In Node.js applications, horizontal scaling is often used to improve fault tolerance and scalability, for example, through clustering and distributed databases.