Re: "NEVER" cautioned to auto_explain's log_analyze parameter on Production

On Wed, Feb 26, 2020 at 4:17 PM Jacque <jacqueedmund(at)gmail(dot)com> wrote:

> I've seen it said to "NEVER" apply auto_explain's log_analyze parameter
> on Production. I get the general foreboding doom that can be beset by
> a highly looping control structure eating up disk space (with no
> indication of its exit condition time) but is genrous-disk-writes
> pretty much the only reason for avoiding this in folk's opinion?

log_analyze doesn't take up dreadful amounts of disk
space. log_min_duration and sample_rate are how you control disk usage.

Some systems (combination of hardware and kernel) have slow clock access,
and turning on log_anayze will greatly slow down your CPU-bound queries on
such systems (I've seen as much as 10x slower), even the queries that end
up not meeting log_min_duration. If you are running a modern kernel on
modern hardware, that probably isn't a problem. It will still down queries
by some amount, but probably not enough to matter, assuming the information
it produces is valuable to you.

Cheers,

Jeff