On Aug 21, 2024 19:17, Robert Haas <robertmhaas@gmail.com> wrote:

On Wed, Aug 21, 2024 at 12:31 PM Tomas Vondra <tomas@vondra.me> wrote:
> Anyway, I took a look and the basic idea is simple - when shuffling
> tuples between batches in a hash join, we're currently deforming the
> tuple (->slot) we just read from a batch, only to immediately form it
> (slot->) again and write it to the "correct" batch.

Does skipping this cause any problem if some attributes are toasted?

I suppose not, just something to think about.

I don't see why would this cause any such problems - if anything has to be done when forming the tuples, it had to be done the first time. Shuffling tuples to a different batch may happen, but AFAIK it's really just a copy.

Tomas Vondra