I've just had a rummage around, but I haven't yet found my notes from the early nineties so I can't give you a full list. (I had to give up after sneezing at the dust!) However, the page Object Database should be a good starting point. I was going to give you a couple of examples that I could remember, but it seemed unfair to single them out since the people who worked so hard on them are still in the industry, probably, and my points were general, rather than aimed at the two whose names I can remember! (Also, one of them has actually limped on to the present day, evidently after being bought a few times) Nobody had invented the 'NoSQL' umbrella term then.