Google revving up. Photo: bianconero/Flickr

Google was at the forefront of the NoSQL movement, an effort to build a new breed of database that can spread epic amounts of data across a sea of low-cost servers. But it has now acknowledged that SQL is still alive and well.

On Thursday, the company added a good old fashioned SQL database to Google App Engine, a means of building and hosting applications atop Google’s online infrastructure. The Google infrastructure is underpinned by the company’s proprietary NoSQL database — BigTable — but many developers had balked at using its new-age data model because it wasn’t what they were used to and it didn’t let them easily move existing relational databases on the service.

“You can now choose to power your App Engine applications with a familiar relational database in a fully-managed cloud environment,” read a blog post from Navneet Joneja, Product Manager for the new database, known as Google Cloud SQL. “This allows you to focus on developing your applications and services, free from the chores of managing, maintaining and administering relational databases.”

In similar fashion, Amazon’s Web Services cloud offered a NoSQL database — SimpleDB — for many years, before offering good ol’ MySQL as well.

Google Cloud SQL is now a “limited preview”, meaning it’s only available to certain users. For the moment, it’s free, but after it leaves preview, Google will likely slap a price tag on it, giving businesses and developers at least 30 days notice.

Whereas relational databases were built to run on single machines, NoSQL databases – including MongoDB and Cassandara as well as BigTable and its open source doppleganger HBase — are meant to “scale” across vast numbers of servers so they can accomodate the mountains of data facing companies in the internet age. The flip side is that SQL databases – which order data into neat rows and columns – give you more ways to slice and dice your data.

Google’s move comes just as Oracle was moving in the opposite direction. On Monday, Oracle — the bulkhead of the SQL world — revealed its own NoSQL database, rolling it into a new hardware contraption known as the Oracle Big Data Appliance. The world still needs SQL, but it needs NoSQL too.