I highly recommend the Third Manifesto. I could link this under most posts in this thread but I'll limit myself to two. https://www.dcs.warwick.ac.uk/~hugh/TTM

I highly recommend the Third Manifesto. I could link this under most posts in this thread but I'll limit myself to two. https://www.dcs.warwick.ac.uk/~hugh/TTM/DTATRM.pdf https://www.dcs.warwick.ac.uk/~hugh/TTM/DTATRM.pdf The only problem there is that you might want to use a D language, and well. You can't. There was a product called Dataphor which one can find some writeups on but, baffling though I find this, there are no robust open-source relational databases which use a D language.