<furuyao@pm.nttdata.co.jp> writes:
> When we specify a value which exceeds valid range in "Customized Options" ,
> its behavior is different from "Parameter Interaction via Configuration File" behavior.
> In case of "Parameter Interaction via Configuration File", it finish with FATAL error when it get threshold error.
> But in "Customized Options", it just printout WARNING and continue the process with default value.
I think this is based on a misunderstanding. Bad values in
postgresql.conf only result in a FATAL error at initial postmaster
startup; if you change them and SIGHUP the server, an erroneous new
value just results in a WARNING. This is because we don't really
want the server crashing once it's up. The case you're showing with
registering a new background worker is something that happens after
the server is up, so it's consistent for it to produce a WARNING
not a fatal error.
regards, tom lane