Re: Overhauling GUCS

Josh Berkus <josh(at)agliodbs(dot)com> writes:
> Currently, PostgreSQL,conf and our set of GUC configurations suffer from
> 4 large problems:

> 1. Most people have no idea how to set these.
> 2. The current postgresql.conf file is a huge mess of 194 options, the
> vast majority of which most users will never touch.
> 3. GUCS lists are kept in 3 different places (guc.c, postgresql.conf,
> and the settings.sgml), which are only synched with each other manually.
> 4. We don't seem to be getting any closer to autotuning.

The proposal doesn't actually solve any of those problems.

> Here's a list of the things we want to change. It's all a package and
> should make sense if you take all the changes as a whole.

> 1) Add several pieces of extra information to guc.c in the form of extra
> "gettext" commands: default value, subcategory, long description,
> recommendations, enum lists.
> 2) Incorporate this data into pg_settings
> 3) Delete postgresql.conf.sample
> 4) Add a script called pg_generate_conf to generate a postgresql.conf
> based on guc.c and command-line switches (rather than
> postgresql.conf.sample), which would be called automatically by initdb.

I disagree with doing any of this. It doesn't result in any useful
reduction in maintenance effort, and what it does do is make it
impossible to keep control over the detailed layout, formatting,
commenting etc in a sample postgresql.conf. Nor do I think that
"generate a whole config file from scratch" is going to be a useful
behavior for tuning problems --- how will you merge it with what
you had before?

regards, tom lane