Re: explaining "context" column of pg_settings

Josh Kupershmidt <schmiddy(at)gmail(dot)com> writes:
> The six different kinds of contexts in the pg_settings system view
> aren't terribly well documented. The current doc page says only:
> "Context required to set the parameter's value". A search through the
> archives turned up only a brief explanation[1] of what "postmaster"
> means for this setting. The recent book "PostgreSQL 9.0 High
> Performance"[2] complains "The context field isn't documented very
> well in the official manual."

> I've put together a patch to help document these values based on the
> comments in guc.h, the explanations in [2], and my own understanding.
> My crude explanations could probably use some further wordsmithing and
> check for accuracy :-)

I did some work on this patch and attach an updated version. I'm not
however convinced that it's a good idea to bury this material in
catalogs.sgml --- I think few people ever read that chapter. Shouldn't
we put this into config.sgml instead, somewhere in section 18.1?

> I avoided just copy-pasting from guc.h, particulary because some of
> the explanations struck me as confusing or incorrect.

Well, your replacement explanations seemed even less correct ;-).
Also, I think what the text needs to emphasize is *how* to change
each setting type, so that prompted some of my editing.

regards, tom lane