The future of the database is Open Source. A glance at the 2022 Stack Overflow survey of around 70,000 code-wranglers shows nearly all pros use one of the two leading open source RDBMSes, PostgreSQL (46.5 percent) or MySQL (45.7 percent), although they use other systems as well.
Oracle, which built a global software empire starting with an RDBMS, is only used by about 12 percent of developers, while Db2, the IBM data workhorse used by banks and global retailers, is only used by 2 percent.
There is no question that the leading edge is open source – the people who build new systems are making it so by their choice. The question is why they are achieving dominance among devs.
Peter Zaitsev, CEO of database consultancy Percona, was an early employee of MySQL AB under the leadership of original open source database author Michael "Monty" Widenius. To Zaitsev, it is a question of economics in the startup scene of the early Noughties.
"If you look at Oracle and Db2, they can be very, very expensive systems. In the early 2000s, just after the dotcom era, the new generation of startups, starved of capital, needed but could not afford Oracle, Db2 or SQL Server," he says.
But in going with open source databases, this new generation of startups – Facebook, Uber, and Google among them – began to find they could adapt the system to their own needs, contributing to the open source code, while benefiting from development elsewhere in the community.
"This is permissionless innovation, and your ability to really customize and improve the software with the community is very important," Zaitsev says.
Fast-forward a decade, and this cohort of startups have – as well as attracting billions of users, drawing the attention of financial markets, and fascinating digital transformation gurus – begun to dominate the mindshare of web-native developers.
"The startup developer culture started to permeate through a whole ecosystem because people are looking at the approach Google, Airbnb or Uber might take," Zaitsev says.
"That gets mindshare of the database space. It's moved to open source databases. You will probably be hard-pressed to find some really cool system based on Oracle as a backend database. It might be very important but very boring in the belly of an enterprise and government agency. That is all well and good, but not what developers aspire to."
PostgreSQL and MySQL have more than 50 years of development between them, but a new generation of open source databases have appeared on the market and provoked intense debate around their approach to the open source model.
MariaDB, a fork of MySQL, and CockroachDB, a distributed RDBMS, adopt what they call a Business Source License (BSL). This is a "new alternative to closed source or open core licensing models," according to MariaDB's definition. The source code is always publicly available and non-production use of the code is always free, and the licensor can also make an Additional Use Grant allowing limited production use. Source code is guaranteed to become open source at a certain point in time.
Meanwhile, MongoDB, the popular document-based NoSQL database, offers the Server Side Public License (SSPL) v1.0 which requires that enhancements to MongoDB be released to the community. The restrictions mean a company cannot offer MongoDB as a managed service to other users.
Neither SSPL or BSL meet all criteria for open source software set by the Open Source Initiative (OSI).
Zaitsev says the approach of these firms is partly a result of investors gravitating towards the idea of open source.
"Money can create reality. That can be a danger for open source. There are regions of the open source movement that are kind of romantic and want to change the world. Now, commercial open source is about making money. Yeah, people think open source is good: that is something that we learned over 20 years.
