Tamr, a startup with software for connecting data sets, announced today a $25.2 million round. Several strategic investors are participating: HP Ventures, Thomson Reuters, and MassMutual Ventures, the venture arm of Massachusetts Mutual Life Insurance.

HP’s involvement in Tamr is not a big surprise. Tamr cofounders Michael Stonebraker and Andy Palmer previously started database company Vertica, which HP acquired in 2011. Thomson Reuters, meanwhile, is a Tamr customer.

Tamr’s new funding round comes three months after Stonebraker, a database luminary, was named this year’s winner of the prestigious A.M. Turing Award from the Association for Computing Machinery.

Tamr’s software accepts data from a wide variety of sources, including the Hadoop open-source file system. It uses machine learning to automatically figure out the relationships that exist among many data sources. And to be as accurate as possible, Tamr also relies on people working at companies to provide their expertise on the data.

Tamr is one of a few startups with tools that people can use to get their data ready for analysis with business-intelligence applications. Metanautix, Paxata, and Trifacta also come to mind.

Cambridge, Massachusetts-based Tamr started in 2013 and launched at VentureBeat’s 2014 DataBeat conference.

In addition to the strategic investors in the new round, existing investors Google Ventures and New Enterprise Associates also participated, as did SineWave Ventures and Work-Bench Ventures. To date the startup has raised $42.4 million.