Rackspace (NYSE: RAX) is the latest company to make an investment NoSQL database-as-a-service (DBaaS) provider Cloudant. The Rackspace investment of an undisclosed sum follows three months after Samsung Ventures made a similar strategic investment in the company.

According to a blog post by Pat Matthews, Rackspace’s senior vice president of Corporate Development, the investment in Cloudant has been made to reinforce the important of DBaaS and to help developers spend their time on building new features rather than maintaining databases.

That’s where Cloudant’s DBaaS comes into play. The service was designed to “let developers focus on new development and not on operations.”

The Rackspace investment comes five months after Cloudant launched its NoSQL DBaaS offering on Rackspace’s open cloud platform as part of the Rackspace Cloud Tools program. Rackspace markets its own brand of Rackspace Cloud Databases, but as we noted on Talkin’ Cloud in February, the Cloudant DBaaS offering complements rather than competes with the Rackspace offering. And that seems even clearer now that Rackspace has funneled some cash into the NoSQL DBaaS provider.

Or maybe Rackspace has its eye on a future acquisition. As Matthews mentioned in his blog post, Rackspace acquired NoSQL database provider ObjectRocket earlier this year to ramp up its MongoDB databases. Perhaps Rackspace wants to continue building out its NoSQL DBaaS services. But that’s only wild speculation.

Rackspace and Cloudant have been partners for some time, and through the investment, Rackspace will help its partner “grow in its service, its people and its customers—many of whom are also Rackspace customers,” Matthews wrote.

One of the problems Cloudant aims to help solve is the management of Big Data, and Matthews wrote that “there is a major opportunity for managed, hosted databases as more mobile and web apps move to a NoSQL mode.”

“Our goal at Rackspace is to provide developers the best tool for the job. With the number of NoSQL database variants exploding, there’s not a one-size-fits-all solution,” Matthews wrote. There rarely is a one-size-fits-all solution. Rackspace seems to be on the lookout for complementary solutions that will meet the needs of its cloud customers.