Обсуждение: Re: BUG #18965: Issue with Short-Circuit Evaluation in Boolean Expressions

The following bug has been logged on the website:

Bug reference:      18965
Logged by:          Todd Brandys
Email address:      brandystodd@gmail.com
PostgreSQL version: 17.5
Operating system:   Linux
Description:       

In the circumstance where a function evaluation is performed within Boolean
expression, the evaluation seems to continue past a function returning a
TRUE value.

On Fri, 2025-06-20 at 11:14 -0700, David G. Johnston wrote:
> > In the circumstance where a function evaluation is performed within
> > Boolean
> > expression, the evaluation seems to continue past a function
> > returning a
> > TRUE value.
> >
>
> Where did we claim we perform short-circuiting?

Even if you force the execution-time evaluation order with CASE, you
can still get an error:

EXPLAIN SELECT CASE WHEN random() < 2 THEN TRUE ELSE (1/0 = 0) END;
ERROR:  division by zero

The expression "random() < 2" is always true, so at execution time the
second branch will never be reached. But it is reached at planning
time.

Regards,
    Jeff Davis