Re: Send duration output to separate log files

On Wed, 10 Jul 2024 at 16:58, Greg Sabino Mullane <htamfids(at)gmail(dot)com>
wrote:
--snip--

> Why not build a more generic log filtering case?
>
> I looked into this, but it would be a large undertaking, given the way our
> logging system works. And as per above, I don't think the pain would be
> worth it, as duration covers 99% of the use cases for separate logs.
>

The other category of logging which would benefit from a separate file is
audit. It also can create massive volumes of log content. Splitting audit
information off into a separate file for use by a separate team or function
is also a request I have heard from some financial institutions adopting
Postgres. With audit being provided by an extension, this would become
quite an intrusive change.

Why not use an extension for this?
>
> I did start this as an extension, but it only goes so far. We can use
> emit_log_hook, but it requires careful coordination of open filehandles,
> has to do inefficient regex of every log message, and cannot do things like
> log rotation.
>

Would an extension be able to safely modify the message_type field you have
added using emit_log_hook? If so, the field becomes more of a log
destination label than a type marker. If an extension could hook into the
log file creation/rotation process, that would be a nice basis for enabling
extensions (I'm particularly thinking of pgAudit) to manage separate
logging destinations.