Relational databases, such as MySQL, PostgreSQL and various commercial products, have served us well for many years. Lately, however, there has been a lot of discussion on whether the relational model is reaching the end of its life-span, and what may come after it.
Using MongoDB to implement tree structures has some advantages, but as it lacks features that traditional RDBMSes have (like table locking and transactions), it is easy to create race conditions during simultanous operations. This is a pretty generic problem and I hope we can emphasize common problems and best practices on the implementation of thread-safe tree tables here.
describes the four Oracle Database editions and the features available with those editions
summary of oracle editions
Embedded persistent database for Node.js, written in Javascript, with no dependency (except npm modules of course). You can think of it as a SQLite for Node.js projects, which can be used with a simple require statement. The API is a subset of MongoDB's. You can use it as a persistent or an in-memory only datastore.
tl;dr: I have created a test suite for comparing the transaction isolation levels in different databases. I did this as background research for my book. This post explains why.
