Exactly. We sort of backed into this project by starting with HSQL (http://hsqldb.org/ http://hsqldb.org/) a low-end pure-Java "database" that was popular at th

Exactly. We sort of backed into this project by starting with HSQL (http://hsqldb.org/ http://hsqldb.org/) a low-end pure-Java "database" that was popular at the time. The more we used HSQL the more it became clear that it was more like a SQL-parser wrapping a simple key/value store than a full-on ACID database. We created AxionDB precisely because we needed the kinds of capabilities you mention and at the time HSQL did not provide them and wasn't remotely architected to support them. To be honest though, creating a moderately robust RDBMS from "scratch" turned out not to be the most ambitious or complex part of the overarching project that spawned AxionDB. The harder part was trying to use Java's primitive, built-in HTML-renderer to create something approximating a fully featured browser. The effort and complexity behind something like Gecko, WebKit, Edge, Blink, etc. is very easy to underestimate. It's a hard problem, made much harder by having to tackle the kinds of content you find "in the wild. Frankly building a database was a much more straightforward problem than that.