Re: [PATCH] Add session_preload_libraries configuration parameter

Hi,

Peter Eisentraut <peter_e(at)gmx(dot)net> writes:
> This is like shared_preload_libraries except that it takes effect at
> backend start and can be changed without a full postmaster restart. It
> is like local_preload_libraries except that it is still only settable by
> a superuser. This can be a better way to load modules such as
> auto_explain.

I had a pretty hard time to get my head around that new one, and I'm not
sure I totally did. The important things to me are:

- No need to manually copy the lib into the plugin directory,
- ALTER ROLE support.

So basically it's a very good solution for auto_explain and any other
module you want to load eagerly but not for everyone and when not using
shared memory.

I have a feeling that something simpler could be made, but I will have
to continue thinking about it.

I found it strange that those two paras read differently for saying the
same thing?

> + preloaded at connection start. This parameter cannot be changed after
> + the start of a particular session. If a specified library is not

> + The parameter value only takes effect at the start of the connection.
> + Subsequent changes have no effect. If a specified library is not

Will review the code in more details, wanted to get back on the context
where this patch is useful first, and try to understand better the trade
offs involved.

Regards,
--
Dimitri Fontaine
http://2ndQuadrant.fr PostgreSQL : Expertise, Formation et Support