On Fri, May 22, 2020 at 10:59 PM David G. Johnston <
david.g.johns...@gmail.com> wrote:
> On Friday, May 22, 2020, Richard Guo wrote:
>
>> Hi hackers,
>>
>> For EXISTS SubLink, in some cases the subquery can be reduced to
>> constant TRUE or FALSE, based on the knowledge that it's being used in
>
On Friday, May 22, 2020, Richard Guo wrote:
> Hi hackers,
>
> For EXISTS SubLink, in some cases the subquery can be reduced to
> constant TRUE or FALSE, based on the knowledge that it's being used in
> EXISTS(). One such case is when the subquery has aggregates without
> GROUP BY or HAVING, and w
Hi hackers,
For EXISTS SubLink, in some cases the subquery can be reduced to
constant TRUE or FALSE, based on the knowledge that it's being used in
EXISTS(). One such case is when the subquery has aggregates without
GROUP BY or HAVING, and we know its result is exactly one row, unless
that row is
