Re: Memoize ANTI and SEMI JOIN inner

On 3/31/25 05:33, David Rowley wrote:
> I can't say definitively that we won't find a reason in the future
> that we should set inner_unique for SEMI/ANTI joins, so I don't follow
> the need for the Assert.
>
> Maybe you're seeing something that I'm not. What do you think will
> break if both flags are true?
I considered targeting PG 19 and July Comitfest for this feature, but
currently, I don't see any further development needed here. What are
your thoughts, David? Does it make sense to commit this to PG 18?

I have no reason to rush the process, but this feature seems beneficial
for practice. When the internal structure is a bushy join tree,
producing even a single tuple can be costly. SQL Server's Spool node
addresses this issue, and people sometimes experience confusion
detecting degradation during migration with specific queries.

--
regards, Andrei Lepikhov