David Rowley <dgrowleyml@gmail.com> writes:
> On Thu, 30 Sept 2021 at 10:09, Tom Lane <tgl@sss.pgh.pa.us> wrote:
>> 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.
I'm still confused. AFAICS, the top-level operator of the qual clause has
exactly nada to do with the cache keys, as this example makes plain.
regards, tom lane
