Here's How It Feels To Leave A High-Paying Job At Facebook For Your Own Startup

In the winter of 2011, Eric Frenkiel was working at Facebook as an engineer making tons of money and sitting on lots of pre-IPO stock options.

Then he, along with fellow Facebook engineer Nikita Shamgunov, walked away.

They left to found a startup called MemSQL, which is taking on giant Oracle with a faster, cheaper database. He was 25.

MemSQL offers a commercial version of the database that Facebook built for itself. (Before Facebook, Shamgunov also helped Microsoft build its database competitor to Oracle, Microsoft's SQL Server).

It was hard to leave Facebook and the financial comforts it held, Frenkiel told Business Insider. And his friends and family told him he was crazy to consider it. But he left anyway.

"I've always believed that you always regret what you didn't do, not what you did. I knew if I hadn't done this decision, I'd always kick myself," said Frenkiel, the now 28-year-old CEO of MemSQL.

But even from the start, there were signs that MemSQL could be a big success. For instance, it's the first enterprise company accepted into the Ycombinator program, he told us.

Plus, the tech is in a hot enterprise area called the "in-memory database," meaning that all of the data is stored in RAM, not on hard disks. SAP is having big success taking on Oracle with its in-memory database called HANA. But MemSQL runs on ordinary, low-cost commodity servers, and doesn't need the expensive specialized hardware that Oracle sells.

Flash forward to this week when the company announced a hefty $35 million investment led by Accel Partners, with participation from Khosla Ventures and existing investors First Round Capital and Data Collective. MemSQL had raised $10 million previously from VCs and a list of famous angels, including SV Angel, Ashton Kutcher, Max Levchin and Aaron Levie.

Frenkiel is careful not to say that MemSQL will one day put the mighty Oracle out of business. He believes there's plenty of room for new database startups and the traditional players, thanks to the "big data" trend.

But he also says that MemSQL on an ordinary server costs about $4,000 per terabyte of data stored, whereas Oracle's latest database, with its new in-memory feature on one of Oracle's specially built servers, can run $10,000 per terabyte stored.

And that's why, in two years, the company has snagged some impressive customers like Comcast, Morgan Stanley, Zynga and ShutterStock.