There is an on-going debate in our community about the best approach for developing cloud-native or data-driven apps. On one side, you have folks who say use a single-purpose “best-of-breed” database for each data type or workload you have. While the other half say, you should use a single converged database. So, which approach is right for you and your projects?
Let’s examine some of the pros and cons of each approach.
Single-purpose databases or purpose-built databases as they are often as known, are engineered to help solve a single or small number of problems. Given their narrow focus, they can ignore the tradeoffs usually required when trying to accommodate multiple data types or workloads. It also allows them to use a convenient data model that fits the purpose and to adopt APIs that seem natural for that data model. They offer less functionality than converged databases, and therefore, fewer APIs, making it easier to start developing against them. Their simplicity means they do a few things very well, but other things not at all. For example, a lot of single-purpose databases scale well, because they offer no strong consistency guarantees.
At first glance, single-purpose databases appear to be a good option. Developers are happy because they get exactly what they need to begin a project. However, when you look at the bigger picture, single-purpose databases can cause a lot of pain and end up costing more in the long run.