Startup vendor MemSQL announced Wednesday a new release of its high-scale, in-memory database that adds JSON (Java Script Object Notation) support. The move is aimed at attracting developers who might otherwise choose the MongoDB NoSQL database.

MongoDB has the leading market share in the burgeoning NoSQL database market, and JSON document handling is that product's stock in trade. So it's no coincidence that database rivals of every description are adding JSON support. The list includes NoSQL vendor Couchbase and relational database vendors IBM DB2 and Oracle MySQL.

MemSQL is a two-year-old company in the so-called NewSQL camp -- vendors trying to blend the scalability of NoSQL databases with relational database attributes including ACID-compliant (atomic, consistent, isolated, durable) transactional performance and convenient SQL querying. Like other NewSQL options (Clustrix, FoundationDB, ScaleDB), MemSQL is a relational database, but its differentiator is the combination of in-memory (optimized for RAM) performance and scale-out massively parallel processing. Its closest competitor is VoltDB, launched in 2009.

MemSQL's JSON move in the 2.5 release is no big surprise as it was part of an earlier release candidate. Native JSON support will enable the database to consume clickstreams and event feeds expressed in JSON, as frequently encountered in high-scale Internet applications.

[ Want more on the latest NoSQL move? Read Couchbase Takes NoSQL Mobile. ]

"Support for JSON means developers can move faster by plugging JSON directly into the system and then use SQL to query, iterate, traverse and index that data," said Eric Frenkiel, CEO of MemSQL, in a phone interview with InformationWeek. "With NoSQL databases it's easy to get data in, but how do you intelligently get data out? That has been a sore point for NoSQL vendors."

In MemSQL's case, the ability to query JSON with SQL comes without the penalty of having to transform that data to a consistent structure, but that's not always the case for rivals, according to Frenkiel, who co-founded MemSQL along with fellow Facebook veteran and CTO Nikita Shamgunov.

MemSQL's 2.5 release also attempts to add NoSQL flexibility with a new online alter table feature. What NewSQL databases typically can't do is match the flexibility of NoSQL databases because they rely on predefined data models to support SQL querying. Frenkiel said the online alter table feature greatly reduces the penalty of adding new dimensions of data a MemSQL data model.

"When you add more data on a disk-based system, it becomes expensive and time consuming to alter tables, but this online alter table feature lets you add a new column to a table without downtime or locking," Frenkiel explained.

MemSQL 2.5 will reach general release in October. MemSQL claims to have "dozens" of customers, with leading lights including Zynga, Shutterstock, Comcast, CPX Interactive and Ziff Davis.