Until recently, CockroachDB’s SQL was suffering from a serious, long-standing bug – a schrödinbug, in fact – in its handling of table and column references. This blog post outlines how fuzz testing uncovered the error, how we discovered that our way of using Go was partly to blame, and how we addressed the issue using a form of strong typing.

CockroachDB’s JOIN: An Early Implementation When our VP of engineering, Peter Mattis, made the decision in 2015 to support SQL, little did he know that the team would get as far as shipping the first implementation of CockroachDB’s JOIN exactly one year after that. A celebration is in order!

Note: this blog post was updated on September 21, 2017. Jails are FreeBSD’s native solution to contain and isolate server processes. They are an alternative to (and predate) Linux cgroups, Solaris zones, and other OS-level process isolation technologies (the technologies that underlie Docker, CoreOS and a few others) .

Adopting a SQL interface for CockroachDB had an unexpected consequence; it forced us to dabble in language design. Most developers working with SQL have heard rumors of a SQL standard, pages upon pages of norms and requirements for all SQL compliant dialects to respect. Based on its existence, it’s natural to draw the conclusion that SQL is fully specified and straightforward to implement. A developer need only carefully follow each step laid out in the standard until they arrive at a working database. It’s a lot like building a couch from IKEA. However, in the months following our decision to create a SQL layer on top of our distributed consistent key-value store, we’ve come to realize that this is far from the truth.

We at Cockroach Labs absolutely love Aphyr’s work. We are avid readers of the Jepsen series – which some know as a high quality review of the correctness and consistency claims of modern database systems, but which we really know as “Aphyr’s hunting tales about the highest profile bugs in our industry.” Most of us read each new blog entry with a mix of thrill, excitement, and curiosity about which new system will be eviscerated and which exotic error will be discovered next.