Re: INTERVAL MINUTE TO SECOND didn't do what I thought it would do

On Wed, Jan 8, 2025 at 2:43 PM Adrian Klaver <adrian(dot)klaver(at)aklaver(dot)com>
wrote:

>
>
> On 1/8/25 11:00 AM, Ron Johnson wrote:
> > PG 14.13
> >
> > The goal of "(now() - query_start)::INTERVAL MINUTE TO SECOND" column is
> > to see how many minutes and seconds ago that the query started. (Why?
> > Because that's useful to me, and the people I show the output to when
> > queries run for more than a few minutes. We don't need to see hours and
> > days; just the total MMMMM:SS.mmm.)
> >
> > I'd hoped that ::INTERVAL MINUTE TO SECOND would do the trick, but
> > MINUTE TO SECOND seems to be ignored.
>
> From here:
>
>
> https://www.postgresql.org/docs/current/datatype-datetime.html#DATATYPE-INTERVAL-INPUT
>
> "Also, field values “to the right” of the least significant field
> allowed by the fields specification are silently discarded. For example,
> writing INTERVAL '1 day 2:03:04' HOUR TO MINUTE results in dropping the
> seconds field, but not the day field."
>

I read that, but it did not mention that the day values are retained.

> >
> > Is there cast magic that does what I want?
>
> The only way I can think of extract the epoch from the interval and pass
> to a function that builds what you want.
>

I was afraid of that. Must decide if it's worth the time.

> >
> > TAPc=# select pid
> > ,datname as db, usename
> > ,to_char(query_start, 'YYYY-MM-DD HH24:MI:SS.MS <http://SS.MS>')
>
> > as qry_start
> > ,(now() - query_start)::INTERVAL MINUTE TO SECOND as qry_elapsed
> > ,cast(state as char(11)) as state
> > from pg_stat_activity
> > WHERE pid != pg_backend_pid()
> > and state != 'idle';
> > pid | db | usename | qry_start |
> > qry_elapsed | state
> >
> ---------+------+------------+-------------------------+-------------------------+-------------
> > 657996 | | replicator | 2024-11-11 21:03:00.992 | 57 days
> > 16:38:22.342449 | active
> > 4070070 | TAPc | TAP | 2025-01-08 13:41:23.202 |
> > 00:00:00.132817 | active
> > 4070069 | TAPc | TAP | 2025-01-08 13:41:23.140 |
> > 00:00:00.194222 | active
> > 4070065 | TAPc | TAP | 2025-01-08 13:41:23.238 |
> > 00:00:00.096418 | active
> > (4 rows)
> >
> >
> > --
> > Death to <Redacted>, and butter sauce.
> > Don't boil me, I'm still alive.
> > <Redacted> lobster!
>
> --
> Adrian Klaver
> adrian(dot)klaver(at)aklaver(dot)com
>

--
Death to <Redacted>, and butter sauce.
Don't boil me, I'm still alive.
<Redacted> lobster!