Re: per backend I/O statistics

At Tue, 03 Sep 2024 15:37:49 +0900 (JST), Kyotaro Horiguchi <horikyota(dot)ntt(at)gmail(dot)com> wrote in
> When I first looked at this patch, my initial thought was whether we
> should let these stats stay "fixed." The reason why the current
> PGSTAT_KIND_IO is fixed is that there is only one global statistics
> storage for the entire database. If we have stats for a flexible
> number of backends, it would need to be non-fixed, perhaps with the
> entry for INVALID_PROC_NUMBER storing the global I/O stats, I
> suppose. However, one concern with that approach would be the impact
> on performance due to the frequent creation and deletion of stats
> entries caused by high turnover of backends.

As an additional benefit of this approach, the client can set a
connection variable, for example, no_backend_iostats to true, or set
its inverse variable to false, to restrict memory usage to only the
required backends.

regards.

--
Kyotaro Horiguchi
NTT Open Source Software Center