Re: *very* inefficient choice made by the planner (regarding

On Thu, 10 Jun 2004, Stephan Szabo wrote:

>
> On Thu, 10 Jun 2004, Jean-Luc Lachance wrote:
>
> > I agree, but it should be a simple rewrite. No?
>
> It's NULLs inside the subselect that are the issue.
>
> select 1 in (select a from foo)
> select exists ( select 1 from foo where a=1)
>
> If foo.a contains a row with NULL but no rows containing a 1, the above
> give different results (unknown and exists) and IIRC, exists cannot

Erm that exists should have been false