Re: [HACKERS] pg_stat_activity.waiting_start

On 1/7/17 12:41 PM, Joel Jacobson wrote:
> On Sat, Jan 7, 2017 at 3:25 AM, Greg Stark <stark@mit.edu> wrote:
>> What users need to know is in aggregate how much of the time the
>> database is spending working on their queries is going into different
>> states.
>
> This is a separate feature idea, but I think it's really valuable as well.
>
> Maybe something similar to pg_stat_user_functions?
> But instead grouping by wait_event_type, wait_event, and showing
> accumulated count and sum of waiting time since last stat reset, just
> like the other pg_stat_* views?
>
> Maybe something like this?
>
> \d pg_stat_waiting
>  View "pg_catalog.pg_stat_waiting"
>    Column        |       Type       | Modifiers
> -----------------+------------------+-----------
>  wait_event_type | name             |
>  wait_event      | name             |
>  waiting_counter | bigint           |
>  waiting_time    | double precision |

Yes, I've wanted this many times in the past. If combined with Robert's 
idea of a background process that does the expensive time calls this 
could potentially provide very useful information for even very short 
duration locks.
-- 
Jim Nasby, Data Architect, Blue Treble Consulting, Austin TX
Experts in Analytics, Data Architecture and PostgreSQL
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