Introduction

Back in 1979, AT&T released a lightweight database engine written by Ken Thompson, called DBM (http://en.wikipedia.org/wiki/Dbm). In 1987 Ozan Yigit created a work-alike version, SDBM, that he released to the public domain.

The DBM family of databases has been quietly powering lots of things “under the hood” on various versions of unix. I first encountered it rebuilding sendmail rulesets on an early version of linux.

A group of programmers at SGI, including Larry McVoy, wrote a version based on SDBM, called MDBM, with the twist that it memory-mapped the data.

This is how MDBM came to Yahoo, over a decade ago, where it has also been quietly powering lots of things “under the hood”. We’ve been tinkering with it since that time, improving performance for some of our particular use cases, and adding lots of features (some might say too many). We’ve also added extensive documentation and tests.

And I’m proud to say that Yahoo has released our version back into the wild.

Source code: https://github.com/yahoo/mdbm

Documentation: http://yahoo.github.io/mdbm/

User Group: https://groups.yahoo.com/groups/mdbm-users/