Re: Resetting spilled txn statistics in pg_stat_replication

On 2020/06/13 14:23, Amit Kapila wrote:
> On Fri, Jun 12, 2020 at 6:11 PM Magnus Hagander <magnus(at)hagander(dot)net> wrote:
>>
>> On Fri, Jun 12, 2020 at 10:23 AM Amit Kapila <amit(dot)kapila16(at)gmail(dot)com> wrote:
>>>
>>
>>
>> The problem with "lifetime of a process" is that it's not predictable. A replication process might "bounce" for any reason, and it is normally not a problem. But if you suddenly lose your stats when you do that, it starts to matter a lot more. Especially when you don't know if it bounced. (Sure you can look at the backend_start time, but that adds a whole different sets of complexitites).
>>
>
> It is not clear to me what is a good way to display the stats for a
> process that has exited or bounced due to whatever reason. OTOH, if
> we just display per-slot stats, it is difficult to imagine how the
> user can make any sense out of it or in other words how such stats can
> be useful to users.

If we allow users to set logical_decoding_work_mem per slot,
maybe the users can tune it directly from the stats?

Regards,

--
Fujii Masao
Advanced Computing Technology Center
Research and Development Headquarters
NTT DATA CORPORATION