On 2020-09-29 11:43, Amit Kapila wrote:
On Tue, Sep 29, 2020 at 7:39 AM Masahiro Ikeda
<ikeda...@oss.nttdata.com> wrote:
On 2020-09-28 12:43, Amit Kapila wrote:
> On Mon, Sep 28, 2020 at 8:24 AM Kyotaro Horiguchi
> <horikyota....@gmail.com> wrote:
>>
>> At Mon, 28 Sep 2020 08:11:23 +0530, Amit Kapila
>> <amit.kapil...@gmail.com> wrote in
>> > One other thing that occurred to me today is can't we keep this as
>> > part of PgStat_GlobalStats? We can use pg_stat_reset_shared('wal'); to
>> > reset it. It seems to me this is a cluster-wide stats and somewhat
>> > similar to some of the other stats we maintain there.
>>
>> I like that direction, but PgStat_GlobalStats is actually
>> PgStat_BgWriterStats and cleard by a RESET_BGWRITER message.
>>
>
> Yeah, I think if we want to pursue this direction then we probably
> need to have a separate message to set/reset WAL-related stuff. I
> guess we probably need to have a separate reset timestamp for WAL. I
> think the difference would be that we can have one structure to refer
> to global_stats instead of referring to multiple structures and we
> don't need to issue separate read/write calls but OTOH I don't see
> many disadvantages of the current approach as well.
IIUC, if we keep wal stats as part of PgStat_GlobalStats,
don't we need to add PgStat_ArchiverStats and PgStat_SLRUStats
to PgStat_GlobalStats too?
I have given the idea for wal_stats because there is just one counter
in that. I think you can just try to evaluate the merits of each
approach and choose whichever you feel is good. This is just a
suggestion, if you don't like it feel free to proceed with the current
approach.
Thanks for your suggestion.
I understood that the point is that WAL-related stats have just one
counter now.
Since we may add some WAL-related stats like pgWalUsage.(bytes, records,
fpi),
I think that the current approach is good.
--
Masahiro Ikeda
NTT DATA CORPORATION
