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

I agree, but it should be a simple rewrite. No?

x IS NULL/IS NOT NULL AND/OR NOT EXISTS


Tom Lane wrote:

> Jean-Luc Lachance <jllachan@sympatico.ca> writes:
>
>>If the two statments are functionally equivalent, why can't PG rewrite
>>the "NOT IN" version into the more efficient "NOT EXISTS"?
>
>
> They're not equivalent.  In particular, the behavior in the presence of
> NULLs is quite different.
>
>             regards, tom lane
>