10gen raises $20M for MongoDB in maturing NoSQL space

10gen, the startup focused on commercial support of the open-source MongoDB NoSQL database, has raised $20 million in a Series D funding round. Sequoia Capital led the round, along with Flybridge Capital and Union Square Ventures, which brings 10gen’s total venture backing to more than $31 million. The latest round speaks to the popularity of the MongoDB document database, even as the hype around NoSQL has died down as large organizations familiarize themselves with the various products.

According to 10gen founder and CEO Dwight Merriman, his company now has more than 400 customers, and the free version of its MongoDB distribution experiences more than 100,000 downloads per month. Four hundred customers isn’t exactly in the Oracle range yet, but Merriman told me in a recent interview that that’s not necessarily the goal.

Although it’s still early for the NoSQL market, he explained, the growth rate is pretty rapid, and “there’s enough adoption that it’s pretty clear it’s not a blip.” What he means is that NoSQL databases will be more than a niche market like graph databases and other specialized databases are right now, that it will be a new part of the mainstream database market right alongside traditional relational databases and data warehouses.

Merriman didn’t put a number on how big the market might become, but Don Rippert, the CEO of fellow NoSQL startup Basho, recently told me he thinks NoSQL can account for 40 percent of the overall database market as more companies adopt NoSQL databases over the next few years to handle their growing volumes of unstructured data.

If venture capital is any indication, document-oriented databases such as MongoDB and CouchDB will account for much of the NoSQL market share. Aside from 10gen’s $31.4 million, Couchbase (a company selling a combination of CouchDB and the Membase key-value store) has raised $30 million. Merriman chalks up his company’s fundraising success to MongoDB’s capabilities, which have attracted large users such as Disney (s dis), Viacom (s via) and the New York Times. (s nyt)

With the new funding, he said 10gen will expand its global footprint with offices in Europe and Asia, and it will work to build new capabilities into MongoDB, including aggregation and full-text search.