
\dconfig without an argument originally printed all parameters, but it seems more useful to print only those parameters with non-default settings. You can easily get the show-everything behavior with "\dconfig *", but that output is unwieldy and seems unlikely to be wanted very often. Per suggestion from Christoph Berg. Discussion: https://postgr.es/m/YlFQLzlPi4QD0wSi@msg.df7cb.de