Bruce Momjian <bruce@momjian.us> writes:
> The second idea is the idea of having one parameter depend on another.
> Not only could we do that for some of our existing parameters, but we
> could have pseudo-parameters like concurrent_queries, memory_usage, and
> extra_disk_space that could be at the top of postgresql.conf and then
> affect the other settings.
We have tried to do that in the past, and it didn't work well *at all*.
The idea has a fundamental logical flaw, which is that it's not clear
which parameter wins if the user changes both.
regards, tom lane