Re: pgsql: Don't consider newly inserted tuples in nbtree VACUUM.

On 2021-Mar-11, Peter Geoghegan wrote:

> On Thu, Mar 11, 2021 at 12:39 PM Alvaro Herrera <alvherre(at)alvh(dot)no-ip(dot)org> wrote:
> > Given the short life of recheck_on_update I don't think we should
> > consider it a precedent.
>
> Now we have a useful precedent. Apparently there is no way to truly
> remove a storage parameter.

Well, if anybody would write this code:

> > [...] It would be slightly better to ignore it on input (ie. make
> > ALTER TABLE SET a no-op for that case), but I don't think we have
> > code to do that.
>
> That would be better, certainly.

then we could wait until the last release that supported the parameter
goes out of support. (So if we had decided to keep recheck_on_update in
pg11, we could remove it in pg17).

> That seems a little annoying, but not worth spending too much time on.

I guess it'd require that somebody is sufficiently annoyed about the few
lines that supporting a no-op reloption requires. Considering that we
haven't even got the code to release HEAP_MOVED_IN/HEAP_MOVED_OFF, which
has been theoretically possible for ages, I'm not holding my breath.

--
Álvaro Herrera Valdivia, Chile