No to SQL? Anti-database movement gains steam

Computerworld - The meet-up in San Francisco last month had a whiff of revolution about it, like a latter-day techie version of the American Patriots planning the Boston Tea Party.

The inaugural get-together of the burgeoning NoSQL community crammed 150 attendees into a meeting room at CBS Interactive.

Like the Patriots, who rebelled against Britain's heavy taxes, NoSQLers came to share how they had overthrown the tyranny of slow, expensive relational databases in favor of more efficient and cheaper ways of managing data.

"Relational databases give you too much. They force you to twist your object data to fit a RDBMS [relational database management system]," said Jon Travis, principal engineer at Java toolmaker SpringSource, one of the 10 presenters at the NoSQL confab (PDF).

NoSQL-based alternatives "just give you what you need," Travis said.

Open source rises up

The movement's chief champions are Web and Java developers, many of whom learned to get by at their cash-strapped startups without Oracle by building their own data storage solutions, emulating those being built by Google Inc. and Amazon.com Inc., and which they subsequently released as open source.

Now that their open source data stores manage hundreds of terabytes or even petabytes of data for thriving Web 2.0 and cloud computing vendors, switching back is neither technically, economically or even ideologically feasible.

"Web 2.0 companies can take chances and they need scalability," said Johan Oskarsson, the London-based organizer of the NoSQL meeting and, like most of the other attendees, a Web developer (of music streaming site Last.fm). "When you have these two things in combination, it makes [NoSQL] very compelling."

Many, said Oskarsson, had even dumped the open-source MySQL database, a long-time Web 2.0 favorite, for a NoSQL alternative, because the advantages were too compelling to ignore.

Facebook, for instance, created its Cassandra data store to power a new search feature on its Web site rather than use its exisiting database, MySQL. According to a presentation by Facebook engineer Avinash Lakshman (PDF document), Cassandra can write to a data store taking up 50GB on disk in just 0.12 milliseconds, more than 2,500 times faster than MySQL.

What is NoSQL (technically speaking)?

The names of these projects are as diverse as they are whimsical: Hadoop, Voldemort, Dynomite, and others.

Don't call them databases. Amazon.com's CTO, Werner Vogels, refers to the company's influential Dynamo system as a "highly available key-value store." Google calls its BigTable, the other role model for many NoSQL adherents, a "distributed storage system for managing structured data."

They can blow through enormous amounts of data. Hypertable, an open-source column-based database modeled upon BigTable, is used by local search engine Zvents Inc. to write 1 billion cells of data per day, according to a presentation by Doug Judd (PDF document), a Zvents engineer.

Meanwhile BigTable, in conjunction with its sister technology, MapReduce, processes as much as 20 petabytes of data per day.

"Definitely, the volume of data is getting so huge that people are looking at other technologies," said SpringSource's Travis, whose 'VPork' technology helps NoSQL users benchmark the performance of their database alternative.