There's a pretty in-depth overview of that here: https://people.eecs.berkeley.edu/~brewer/cs262/SystemR.pdf https://people.eecs.berkeley.edu/~brewer/cs262/Syste

There's a pretty in-depth overview of that here: https://people.eecs.berkeley.edu/~brewer/cs262/SystemR.pdf https://people.eecs.berkeley.edu/~brewer/cs262/SystemR.pdf Where the original Sequel authors took their Sequel spec and implemented it on real hardware + software, with interfaces for both "non-technical" ad-hoc queries as well as integration with PL/1 and COBOL for more technical users. I have "non-technical" in quotes since in that 1970/80's timeframe, you had to be pretty technical to even have that label.