Very good morning! If, in 2018 when the human structures are very close to reach the edge of our universe, here on earth you are asking me (a simple end-user), in order to run the following "complicated" and "sophisticated" SQL statements: INSERT INTO my_table(key, value, expiry) VALUES ('my_key', 'my_value', 10); SELECT value FROM my_table where key = LOWER('my_key'); ten (10) times in total, to activate the debugger and check the log files because the errors given to me were **totally wrong** ("KEY is NULL" was not NULL) and **misleading**, then one more time: It´s TRAGIC! I, of course, recognise that I have made plenty mistakes! But, I could never imagine that the most advanced open source database in the world would behave in such a "poor" way! @Christoph As regards "rw_redis_fdw" I have to admit the following: - it is honest. It informs the user from the very beginning that "This project is currently work in progress and may have experience significant changes until it becomes stable. Use it with caution and at your own risk!"; although it is so far stable enough!!! - it worked in pg9.x without problem! - the developer did his best when I reported the problem; for my bad luck he did not expirienced the same problem in PG10.x so as he starts searching/debugging from the very first moment. - after **including and NOT fixing** (because there was not any bug) the FuncExpr subquery support, the module has been working fine and it is stable! (until of course the next plan change that PG will induce under the hood and brakes the interface; that´s a joke!) although the developer uses (successfully - I add) very low level, internal interfaces to PostgreSQL as you have already written. And the most important: <h1>The module **DOES** whatever claims to do without a problem, in a very humble way!<h1> As regards the risk of the project, I am aware of it. That´s why I am trying to choose **reliable**, **responsible** and **trustworthy** projects, even if they are not famous! From a very famous project, I just recently got a burn! Do only **ONE** thing but do it **"CORRECTLY"**! I always try to avoid rich-featured projects which, by rule, most of the features are mis-implemented, or quality is poor! As regards database choice, I do not have many options, PG or MariaDB or SQLite. But, when the application is finished, it will be very easy to maintain the application-DB interface and use any other DB. It is a matter of translation. DB is just a tool like any other one, and not a religous matter. In the case of redis fdw I do not have many options. There are two-three of them. Redis is the only db which offers TTL with very high resolution (1 sec), and rw_redis_fdw implements TTL. In addition, at first opportunity, I always contact the developer or the community to get an idea of his/its mentality and the way they work or react or keep their nose up. Have all a nice day! Tia <div id="DAB4FAD8-2DD7-40BB-A1B8-4E2AA1F9FDF2"><br /> <table style="border-top: 1px solid #D3D4DE;"> <tr> <td style="width: 55px; padding-top: 18px;"><a href="http://www.avg.com/email-signature?utm_medium=email&utm_source=link&utm_campaign=sig-email&utm_content=webmail" target="_blank"><img src="https://ipmcdn.avast.com/images/icons/icon-envelope-tick-green-avg-v1.png" alt="" width="46" height="29" style="width: 46px; height: 29px;" /></a></td> <td style="width: 470px; padding-top: 17px; color: #41424e; font-size: 13px; font-family: Arial, Helvetica, sans-serif; line-height: 18px;">Libre de virus. <a href="http://www.avg.com/email-signature?utm_medium=email&utm_source=link&utm_campaign=sig-email&utm_content=webmail" target="_blank" style="color: #4453ea;">www.avg.com</a> </td> </tr> </table> <a href="#DAB4FAD8-2DD7-40BB-A1B8-4E2AA1F9FDF2" width="1" height="1"></a></div>