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Re: Re: ALTER SYSTEM SET command to change postgresql.conf parameters (RE: Proposal for Allow postgresql.conf values to be changed via SQL [review])

Alvaro Herrera <alvherre@2ndquadrant.com>

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From: Alvaro Herrera <alvherre@2ndquadrant.com>
To: Stephen Frost <sfrost@snowman.net>
Cc: Tom Lane <tgl@sss.pgh.pa.us>, Amit Kapila <amit.kapila@huawei.com>, 'Andres Freund' <andres@2ndquadrant.com>, 'Greg Stark' <stark@mit.edu>, 'Fujii Masao' <masao.fujii@gmail.com>, 'Robert Haas' <robertmhaas@gmail.com>, 'Dimitri Fontaine' <dimitri@2ndquadrant.fr>, pgsql-hackers@postgresql.org, 'Josh Berkus' <josh@agliodbs.com>
Date: 2013-08-02T17:34:58Z
Lists: pgsql-hackers 
Stephen Frost escribió:
> * Tom Lane (tgl@sss.pgh.pa.us) wrote:
> > What if you set a combination of parameters that prevents Postgres from
> > starting?
> 
> This was what I was trying to get at up-thread.  Things that prevent PG
> from being able to start (or, really, which cause PG to be started in a
> completely different mode, ala recovery.conf) need to be able to be
> modified outside of PG and therefore should, imv, be considered
> configuration parameters and therefore live outside of $PGDATA (when
> installed from a distro, blah, blah).

I think the way out of this situation is to have a postmaster and/or
pg_ctl switch that disables reading of ALTER SYSTEM settings.  Then the
DBA can do ALTER SYSTEM RESET until it works again.  No need to mess
with "data" files.

-- 
Álvaro Herrera                http://www.2ndQuadrant.com/
PostgreSQL Development, 24x7 Support, Training & Services