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

Le jeudi 29 août 2013 18:42:13 Stephen Frost a écrit :
> On Thursday, August 29, 2013, Andres Freund wrote:
> > If you don't want your installation to use it, tell you ops people not
> > to do so. They are superusers, they need to have the ability to follow
> > some rules you make up internally.
>
> The OPs people are the ones that will be upset with this because the DBAs
> will be modifying configs which OPs rightfully claim as theirs. If they
> have a way to prevent it then perhaps it's not terrible but they'd also
> need to know to disable this new "feature". As for ALTER DATABASE- I would
> be happier with encouraging use of that (or providing an ALTER CLUSTER) for
> those thing it makes sense and works for and removing those from being in
> postgresql.conf. I still feel things like listen_addresses shouldn't be
> changed through this.

ALTER ROLE ALL may be good enougth to handle every GUC that we can also remove
from postgresql.conf (I suppose all GUC needing only a reload, not a restart).
It may needs some improvement to handle changing default for ALL and adding
new role.

> > The energy wasted in a good part of this massive 550+ messages thread is
> > truly saddening. We all (c|sh)ould have spent that time making PG more
> > awesome instead.
>
> Perhaps not understood by all, but keeping PG awesome involves more than
> adding every feature proposed- it also means saying no sometimes; to
> features, to new GUCs, even to micro-optimizations when they're overly
> complicated and offer only minimal or questionable improvements.

Agreed, the current feature and proposal does not include pg_reload, and it
introduces a full machinery we absolutely don't need.

Grammar can be added later when the feature is stable.

So far, we can achieve the goal by using adminpack, by using a file_fdw or a
config_fdw. IMHO it is the job of a FDW to be able to handle atomic write or
anything like that.

I've commented one of the proposed patch adding some helpers to validate GUC
change, I claimed this part was good enough to be added without ALTER SYSTEM
(so a contrib can use it).

--
Cédric Villemain +33 (0)6 20 30 22 52
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