The Open Query GRAPH engine (OQGRAPH) is a computation engine allowing hierarchies and more complex graph structures to be handled in a relational fashion. In a nutshell, tree structures and friend-of-a-friend style searches can now be done using standard SQL syntax, and results joined onto other tables.
No server modifications or SQL syntax extensions are necessary, the engine is implemented as a clean engine plugin for MySQL, MariaDB 5.1 and above, and Drizzle - this means that a standard server binary (mysqld) can be used, and the OQGRAPH plugin loaded at runtime. For MySQL 5.0 (which has no plugin capability) it has to be compiled in, we provide OurDelta builds.
See the OQGRAPH Documentation for more information, downloads, examples, etc.