Re: Logging configuration changes

Peter Eisentraut <peter_e(at)gmx(dot)net> writes:
> On sn, 2009-07-12 at 22:55 +0300, Peter Eisentraut wrote:
>> On occasion, I would have found it useful if a SIGHUP didn't only log *that*
>> it reloaded the configuration files, but also logged *what* had changed
>> (postgresql.conf changes in particular, not so much interested in
>> pg_hba.conf). Especially in light of the common mistake of forgetting to
>> uncomment a changed value, this would appear to be useful.

> Looked into this, looks trivial, except that this would log *all*
> parameters that were set as a result of a reload, instead of only the
> ones that changed. We don't have the information of what it was
> previously readily available.

> I think it would still be useful that way, but some people might find it
> annoying.

Seems to me it would be too chatty to be useful, at least for people who
set more than one or two things in postgresql.conf. Would it be that
hard to track which values actually changed? Without having looked at
the code, I'm thinking that much of the infrastructure must be there
already now that we have support for undoing commented-out settings.

regards, tom lane