On Sunday, engineers and executives from Twitter, PayPal and Verizon discussed their use of MySQL or MySQL Cluster. In each case, MySQL was being used for large high volume, distributed workloads that have been increasingly thought of as the province of NoSQL data stores such as MongoDB and Cassandra.

"A lot of people think they have a big data problem, and a lot of times they don't," said Daniel Austin, who is the chief architect for PayPal. "They have an urge to find a big data solution to a problem, because it looks good."

Austin admits that the typical relational database system (RDMS) architecture has not scaled very well to meet the influx of new data in many organizations, but he cast doubt on the idea that NoSQL data stores provide the answer. "You don't have to give up your relational model to have big data," Austin said.

Paypal itself deals with large amounts of data for its global payment transaction system, which must be fast and accurate. The system must be able to manage 100TB of fixed storage, and once data is written to the system, it must be able to be read from anywhere else in the world in less than a single second. This can be a challenge given that the fastest data can travel between the two most distant places on earth is about 67 milliseconds, thanks to the hard limit of the speed of light. "So that puts a lower bound of how fast things can go," Austin said. The company uses Amazon Web Services, spread across six different locations. All the live data is handled in-memory, rather than being immediately written to disk.

PayPal uses MySQL Cluster for a number of reasons, most notably that true High Availability (HA), which ensures that all the data entered into the system is captured immediately. Another advantage MySQL Cluster offered was scalability.