Re: relationship of backend_start, query_start, state_change

On Thu, Apr 23, 2020 at 9:55 AM David G. Johnston <
david(dot)g(dot)johnston(at)gmail(dot)com> wrote:

> On Thu, Apr 23, 2020 at 9:37 AM Si Chen <sichen(at)opensourcestrategies(dot)com>
> wrote:
>
>> Hello,
>>
>> I'm looking at my pg_stat_activity and trying to figure out what is
>> causing some of these processes. I'm using this query:
>>
>> SELECT pid, wait_event, state_change, backend_start, xact_start,
>> query_start, state_change - query_start, query from pg_stat_activity where
>> datname= 'my_database' and state in ('idle', 'idle in transaction', 'idle
>> in transaction (aborted)', 'disabled');
>>
>>
> Including the "state" field should clear things up considerably.
>
>
> https://www.postgresql.org/docs/current/monitoring-stats.html#PG-STAT-ACTIVITY-VIEW
>
>
>

Specifically, you are including multiple states but then don't look at
which one is actually assigned. You should be able to reason about a
connection mainly from its state and not consider the query at all - it is
a debugging aid only.

David J.