On Thu, 30 Sept 2021 at 10:09, Tom Lane <tgl@sss.pgh.pa.us> wrote:
>
> David Rowley <dgrowleyml@gmail.com> writes:
> > Maybe we can cache the left and the right type's hash function and use
> > the correct one in paraminfo_get_equal_hashops().
>
> Um ... it seems to have correctly identified the cache key expressions,
> so why isn't it just doing exprType on those? The jsonb_exists operator
> seems entirely irrelevant here.
This is down to the caching stuff I added to RestrictInfo to minimise
the amount of work done during the join search. I cached the hash
equal function in RestrictInfo so I didn't have to check what that was
each time we consider a join. The problem is, that I did a bad job of
taking inspiration from check_hashjoinable() which just looks at the
left type.
David