Обсуждение: "NEVER" cautioned to auto_explain's log_analyze parameter onProduction
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? And say a well-mannered connection using it could be safe in production? Seems to be afterall what the pganalyze folks must be doing with their commercial product afterall.
On Wed, Feb 26, 2020 at 4:17 PM Jacque <jacqueedmund@gmail.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