What is the best database for your web application?

MySQL - An open-source relational database management system (RDBMS) known for its reliability, performance, and ease of use. It's widely used in various web applications, ranging from small-scale to large-scale systems.

For me the best database model is MySQL. I use that for more of 8 years and never leave me in trouble. You have infinite possibilities to use this relational database. You have many functions, indexes, foreign keys and much more to organize you project.

NoSQL databases like Mongo & Firestore have gotten a lot of hype over the past few years, and while they are great tools for their intended purpose, I have seen lots of newer developers reach for them by default, using them for things they were not intended for. Platforms like this have better marketing than most relational data solutions and they might seem like a more modern solution, but they have specific applications. They are additional tools, not replacements for relational solutions. If your data has even a moderate number of inter-entity relationships, chances are you'll be better off with a relational database. If not, NoSQL is a great solution.

There are three general archetypes for NoSQL databases - key/value stores such as Redis and Cassandra, document stores such as MongoDB, and graph databases like Neo4J. They all have very different purposes and strengths, and are generally not interchangeable, although there can be a good amount of functionality crossover.

In one of my latest assignments I had a Hybrid scenario where we were using Azure SQL with Geo Redundancy for most of the data in the app, we picked this cause we needed to keep the relational integrity of the data. CosmosDb for large amount of data like audit logs that did not need to be relational, this helped a lot with performance.

Do not slack on this decision. It can affect many things for the entire life of your application. You should be sure to research any third-party software that you intend to use integrates easily with your database of choice. It can also be a helpful idea to have a conversation with your developers to get any input they may have about the decision. Your database selection affects your entire technology stack.

Before deciding on a given database type you need to think about how you can most effectively search and retrieve the data. Each type of database, and each DB engine within a type, is usually optimized for one strategy over others. SQL is great for well-structured data that has been normalized, but document stores or key/value engines are better for unstructured or schema-less data. For example, do you need referential integrity between multiple tables, or should each "record" be a self-contained document? In addition to lookup & retrieval, consider the CAP theorem, ACID properties, replication & backup strategies, and the trade-offs in disk & compute efficiencies for your particular use case. You can't make an informed decision otherwise.

It's very important to consider both cost-at-scale and mobility when choosing a database for your app. Vendor lock-in can be a real killer for businesses of all sizes. Cloud platforms can raise their costs at any time, and if your business can't afford the loss in margin, your only options are to scale down, optimize significantly, jump ship to another solution that is affordable, or go out of business. Oftentimes, the first two options aren't viable or even possible, and if you're locked into a hyper-specific data platform and can't go anywhere else, the only option left is to go out of business. It's also important to consider how much a data solution will cost you when you scale up. The best tech solution isn't always financially viable.