From: | Josh Kupershmidt <schmiddy(at)gmail(dot)com> |
---|---|
To: | pgsql-docs <pgsql-docs(at)postgresql(dot)org> |
Subject: | explaining "context" column of pg_settings |
Date: | 2010-12-05 00:16:49 |
Message-ID: | AANLkTi=rY=Ffo3JkU1eKROG0cDnr0PKaejrEbTSjffnu@mail.gmail.com |
Views: | Raw Message | Whole Thread | Download mbox | Resend email |
Thread: | |
Lists: | pgsql-docs |
Hi all,
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 avoided just copy-pasting from guc.h, particulary because some of
the explanations struck me as confusing or incorrect. For instance:
* not all USERSET options may be set "any time", such as
transaction_isolation if you're already in the middle of a
transaction.
* I found the explanation for BACKEND confusing; it wasn't clear to
me from the comment that a pg_ctl reload would change such settings
for future backends.
I could attempt a patch for the comments in guc.h too, if there's interest.
Cheers
Josh
--
[1] http://archives.postgresql.org/pgsql-admin/2006-05/msg00067.php
[2] p. 126, section "Allowed change context"
Attachment | Content-Type | Size |
---|---|---|
pg_settings_contexts.patch | application/octet-stream | 3.1 KB |
From | Date | Subject | |
---|---|---|---|
Next Message | Chris | 2010-12-07 18:28:44 | Is timestamptz alias documented? |
Previous Message | Alvaro Herrera | 2010-12-03 13:01:28 | Re: Translation of FAQ |