Re: pg_stat_get_activity(): integer overflow due to (int) * (int) for MemoryContextAllocHuge()

Hi,

On 2023-09-28 07:53:45 +0900, Michael Paquier wrote:
> On Wed, Sep 27, 2023 at 10:29:25AM -0700, Andres Freund wrote:
> > Frankly, it seems like a quite bad idea to have such a high limit for
> > pgstat_track_activity_query_size. The overhead such a high value has will
> > surprise people...
> 
> Still it could have some value for some users with large analytical
> queries where the syslogger is not going to be a bottleneck?  It seems
> too late to me to change that, but perhaps the docs could be improved
> to tell that using a too high value can have performance consequences,
> while mentioning the maximum value.

I don't think the issue is syslogger, the problem is that suddenly accessing
pg_stat_activity requires gigabytes of memory. That's insane.

Greetings,

Andres Freund