Oracle. SQL Server. DB2. MySQL. PostgreSQL. Despite the fact that these are the five most popular enterprise databases, they’ve become a bit dull over the past three years. Since the NoSQL movement began in 2010, new data stores have offered such a diverse array of use cases, it would seem that almost any traditional database could now be replaced by some specialized data store.

But despite the NoSQL revolution being the cause of this new springtime for databases, not all the green shoots are NoSQL. There are new databases cropping up, or just now maturing, in all manner of technical areas. There are new graph databases, new time-series databases, highly expandable key-value stores, and even new takes on the relational model.

Like most tools in any type of job, using the right database in the right place can make the difference between success and failure. That’s why choosing a database has gone from being one of the easiest decisions your team has to make to one of the hardest.

So, then, we set out on a trip through this verdant and growing meadow of data stores. Which one is right for you? That depends entirely on your use case.

Springtime for databasesSQL revolution
NoSQL can mean two things: No SQL, or Not Only SQL. It is the latter that many NoSQL companies tout when offering their data stores as a supplement to existing relational databases. But just because you need fast response times and highly scalable transactions doesn’t mean you have to throw SQL out entirely.

Still, the challenges, for both new and old relational database players alike, are to focus on the strengths of your data store, and to make sure developers understand what the best use case for your software is.

Scott Jarr, cofounder and chief strategy officer of VoltDB, said that his company has found the sweet spot for its SQL-based relational data store that focuses on Java-based stored procedures. “I think that we are in a state of incredible noise and confusion in the market, and part of that is a natural stage of a market that is in its early stage and growing fast,” he said. “People are no longer looking at the individual products. Instead, they’re saying ‘I’ve got a particular problem,’ and then they’re starting to look at the databases that are options to them.

“Our challenge has been identifying what that use case is, and figuring out how we talk about it. It’s been quite clear to us as we’ve accelerated that our use case is very simple: It’s high-velocity in-bound transactions, like stocks, or the Web. It’s about making decisions on them in real time, and they’re looking at real-time analytics on it. That was news to us two or three years ago. The real-time analytic component became a very unique third leg to that stool. Being able to look at the analytics in real time is very important.”
Naturally, SQL databases don’t have to live in a vacuum. The moniker “Not Only SQL” is aptly applied in the enterprise, where massive databases aren’t going to be replaced overnight by some hot new NoSQL. But having giant data stores already in place doesn’t limit one’s access to NoSQL technologies. Using NoSQLs as a front for existing databases is a great way to spread the benefits of NoSQL without losing the relational benefits on the back end.