TODO item: Allow more complex user/database default GUC settings - Mailing list pgsql-hackers

From Alvaro Herrera
Subject TODO item: Allow more complex user/database default GUC settings
Date
Msg-id 20090811221921.GK16362@alvh.no-ip.org
Whole thread Raw
Responses Re: TODO item: Allow more complex user/database default GUC settings  (Alvaro Herrera <alvherre@commandprompt.com>)
List pgsql-hackers
Hi,

There's a longstanding TODO item, in subject.  Previous discussion was
here:

http://archives.postgresql.org/pgsql-hackers/2006-09/msg02341.php

In looking what it would take to implement it, I find that it is
trivial.  The only part that looks complex is the UI for it.  Is anyone
interested in giving this patch a shot?

Implementation-side, it requires a new catalog (pg_settings), with the
following columns:

setdatabase    oid
setrole        oid
setconfig    text[]

datconfig and rolconfig are removed.

ALTER DATABASE / SET sets setdatabase to the OID of the database in
command, and setrole to 0 (InvalidOid); ALTER ROLE / SET sets setrole
and leaves setdatabase 0.

A new command allows one to set a config that applies to both database
and role.

At startup, the settings are applied in the following order:
database=value    role=0
database=0    role=value
database=value    role=value

This way, current behavior is maintained (ALTER ROLE trumps ALTER
DATABASE).

The only real work in this is figuring out what the grammar for the new
command looks like.  Maybe we could have some like

ALTER ROLE foo ALTER DATABASE bar SET config

There are of course many possible variations but this looks the most
reasonable one.  Any better ideas?

-- 
Alvaro Herrera                                http://www.CommandPrompt.com/
The PostgreSQL Company - Command Prompt, Inc.


pgsql-hackers by date:

Previous
From: Josh Berkus
Date:
Subject: Re: "Hot standby"?
Next
From: Peter Eisentraut
Date:
Subject: Re: [COMMITTERS] pgsql: Ship documentation without intermediate tarballs Documentation