-----Message d'origine-----
De : Julien Rouhaud <rjuju...@gmail.com>
Envoyé : vendredi 10 septembre 2021 07:18
À : Michel SALAIS <msal...@msym.fr>
Cc : postgres performance list <pgsql-performa...@postgresql.org>
Objet : Re: sql execution time in pg_stat_statements
On Fri, Sep 10, 2021 at 2:49 AM Michel SALAIS <msal...@msym.fr> wrote:
>
> I think that total_time in pg_stat_statements is cpu time + possible waits.
> So, can I say that:
>
> Total_sql_time = total_time + blk_read_time + blk_write_time
>
> Documentation is not clear at all on that.
In version 12 and below, total_time is the elapsed time between the execution
start and stop, so it includes all underlying events. That includes any IO
activity, wait events or nested statements (if pg_stat_statemetns.track is set
to all). This corresponds to the new total_exec_time field in version 13 and
later.
> Just to say that for PostgreSQL 13, total_time is replaced by
> “total_exec_time + total_plan_time”
Indeed, as this version also tracks planning activity.
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Hi,
I thaught that total_time (total_exec_time + total_plan_time) included I/O but
when we have blk_read_time + blk_write_time equals several times total_time it
is difficult to continue to think that...
So What is really total_time (total_exec_time + total_plan_time) ?
