"No practical applications of recursive query theory... have been found to date" - Michael Stonebraker, 1998 Readings in Database Systems, 3rd Edition Stonebraker and Hellerstein, eds.

Datalog fans [1-3] love to use this quote from 20 years ago, then cite a bunch of applications of Datalog to prove Stonebraker wrong. Indeed, researchers came to love Datalog, and can’t seem to get enough of it in DB/PL conferences. Nevertheless, every new Datalog paper [4-7] still uses the same bunch of artificial queries pulled from textbooks (and other papers) as benchmarks, and the best “real world” application is still pointer analysis which is also borne out of academia.

Do people really write recursive queries in the wild (non-recursive Datalog doesn’t count)? What’s the most interesting use of WITH RECURSIVE in SQL you’ve seen?

[1]: https://dsf.berkeley.edu/jmh/tmp/dnsigmod06.pdf

[2]: https://dl.acm.org/doi/pdf/10.1145/3452021.3458815

[3]: https://courses.cs.duke.edu/fall17/compsci516/Lectures/Lecture-21-Datalog-notes.pdf

[4]: https://dl.acm.org/doi/pdf/10.1145/3632928

[5]: https://arxiv.org/pdf/2311.02206.pdf

[6]: https://cs.au.dk/~magnusm/papers/pldi16/paper.pdf

[7]: http://www.rntz.net/files/seminaive-datafun.pdf