BUG #19437: temp_tablespaces doesn't work inside a cursor?

On Wednesday, March 25, 2026, Tom Lane <tgl(at)sss(dot)pgh(dot)pa(dot)us> wrote:

> PG Bug reporting form <noreply(at)postgresql(dot)org> writes:
> > I'm seeing strange behavior in Postgres when changing the
> temp_tablespaces
> > parameter and suspect a bug. At least, I haven't found a description of
> this
> > behavior in the documentation.
>
> I think you are imagining that pg_reload_conf() is a synchronous
> operation.

The use of sleep does indicate awareness of the async nature of this.

>
> > Ensure that temporary files are created in it:
>
> \o /dev/null
>
> What does "\o /dev/null" have to do with this? That's a
> psql-side operation.
>

The comment applies to all three lines in the following block, not just the
first line.

There is something odd here. Look at the log entry at 12:04:08.016; it
uses base/ while the surrounding ones use pg_tblspace/ and the setting
itself hasn’t changed during the sequence.

I haven’t tried to validate the cursor claim yet but; this definitely isn’t
the easiest format to consume and I can’t do much on my own presently.

David J.