Re: another idea for changing global configuration settings from SQL

On 11/16/2012 06:05 PM, Robert Haas wrote:
> On Thu, Nov 15, 2012 at 5:38 PM, Tom Lane <tgl@sss.pgh.pa.us> wrote:
>> Another and probably bigger thing is that SIGHUP is used for settings
>> that do something useful only in background processes (eg checkpointer).
>> Some of those processes are not capable of reading system catalogs at
>> all.  This is particularly a showstopper for settings affecting the
>> postmaster itself, which is most certainly *not* going to grow the
>> ability to read catalogs.
> This seems like a pretty large strike against this whole idea.  In
> fact, I think we might want to abandon this whole approach on this
> basis.
Can't we keep a separate text .conf file specifically for the background
processes which can't read system catalogs. It could contain only the
GUCs these processes are interested in.

This file can be written out via a OnCommit hook which unhooks itself
when the work is done.

This approach should guarantee that the latest committed state is
always in the text file.

Hannu